AWUS01 KWNH 011917
FFGMPD
CAZ000-020700-

Mesoscale Precipitation Discussion 0011
NWS Weather Prediction Center College Park MD
217 PM EST Sat Feb 01 2025

Areas affected...central to northern California

Concerning...Heavy rainfall

Valid 011915Z - 020700Z

SUMMARY...Heavy rain will develop across north-central CA this
afternoon and especially tonight. Rainfall will be steady but with
hourly totals increasing to over 0.5 inches, especially for the
northern Sierra Nevada tonight. 12 hour totals of 3 to 6+ inches
can be expected for the northern Sierra Nevada with 1 to 3 inches
for the Coastal Ranges.

DISCUSSION...A big picture view of Blended Total Precipitable
Water (PW) and MIMIC Total PW showed a southwest to northeast
oriented axis of PW values in excess of 1.5 inches streaming
across HI to about 36N, and extending east to about 127W,
weakening with eastward extent to the West Coast. Land-based GPS
data from 18Z showed that PW values of greater than 1 inch
extended from northern Mendocino County to Santa Barbara County
with a max near 1.25 inches centered around San Francisco Bay and
eastward into the lower Sacramento River Valley. The values within
the core of the moisture axis are well over 200 percent of normal
via the blended imagery.

Placement of a low ot mid-level low over British Columbia and
ridge centered about 600 miles west of the northern Baja Peninsula
has allowed for a funneling of these anomalous moisture values
into the CA coast. A powerful (191 kt at 250mb via 12Z SLE
sounding) zonally oriented upper level jet was sandwiched between
the low to the north and high to the south, with no significant
movement of these two features forecast through early tonight.
Recent GFS, RAP and other guidance are good agreement with the
arrival of a corridor of stronger 850 mb winds (40-50 kt) arriving
into Sonoma and Marin counties over the next 1-2 hours, oriented
perpendicular to the coastline along and just south of a east-west
oriented quasi-stationary front extending offshore of the central
CA coast. Some backing of low level flow toward the southwest is
expected across the Valley into the foothills of the Sierra
Nevada. With the increase in low level flow and a subtle increase
in PW values (up to ~1.4 inches), IVT magnitude is expected to
peak between 800-900 kg/m/s from just north of San Francisco Bay
into the southern Sacramento Valley in the 21Z-02Z time frame. The
surge will be short-lived however and poor low and mid level lapse
rates should limit instability to near zero for coastal and inland
locations through the first half of tonight with rainfall
intensity largely driven by wind speed and orographic lift.

Steady light to moderate rain was ongoing across the coast and
Sierra Nevada of north-central CA as of 18Z but should increase in
magnitude over the next 6 hours, especially into the upslope
regions of the Sierra Nevada where orographic ascent will be
maximized given 700 mb winds peaking in the 70-80 kt range just
after 00Z. 12 hour rainfall totals of 1 to 3 inches are expected
for the Coastal Ranges from just north of San Francisco Bay to
just south of 40N and 3 to 6+ inches for the Sierra Nevada from
roughly Amador to Butte counties. While rainfall through 07Z is
not expected to produce impacts from flooding, heavy rain will
continue through the night with potential for flooding and higher
rain rates to increase prior to 12Z.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5dIiGAeulu1rxK0zydcPEuCyMtNZXnx8os26hae-z-rkAXFPgV4aUFw3fciXn_7RGhfq= v6P58ylRb53IJTNahh-6NHU$ for graphic product...

ATTN...WFO...EKA...HNX...MTR...REV...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 40442163 40302137 40112102 39882047 39442017=20
38772012 38181972 37901960 37541946 37371955=20
37521991 37722010 38022037 38332090 38262158=20
37982207 37892261 37972305 38372341 38722374=20
39002387 39362397 39652383 40062346 40262297=20
40412231=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 020701
FFGMPD
NVZ000-CAZ000-021900-

Mesoscale Precipitation Discussion 0012
NWS Weather Prediction Center College Park MD
200 AM EST Sun Feb 02 2025

Areas affected...Northern California

Concerning...Heavy rainfall

Valid 020700Z - 021900Z

SUMMARY...An atmospheric river aimed at northern California will
continue to produce heavy rain with rates between 1/4 and 3/4
inches per hour possible.

DISCUSSION...An atmospheric river aimed at northern California
will continue to advect tropical moisture from near Hawaii
northeastward into the state today. The moisture has a tropical
connection due to an expansive area of high pressure located off
southern California joining forces with a cold core low off
Vancouver Island to squeeze the moisture into a relatively narrow
corridor (atmospheric river). PWATs between 1 and 1.25 inches are
associated with the moisture plume. This is 4 sigma above the
climatological normal as well as within the 90th to 95th
percentile compared to a 30-year average of PWATs for the area.
IVT values from CW3E GFS and EC guidance are around 800 kg/ms.
Over the past 24 hours, Anywhere from 1 to 4 inches of rain have
fallen across northern California, with the highest values in the
Sierras around and west of the Lake Tahoe region. NASA Sport soil
moisture imagery shows much of the surface soil layer has
saturated significantly compared to 24 hours ago, so most of the
rain that falls from here should convert to runoff.

Radar imagery shows a plume of rainfall occurring over much of far
northern California with rates generally between 1/10 and 1/4 inch
per hour ongoing. These rates are confirmed by the numerous
weather stations set up across northern California. A stationary
front draped over northern California (not shown) delineates the
remarkable surface convergence occurring within this atmospheric
river, with winds off the coast of Crescent City 20 kts out of the
north, and winds both off the coast of Mendocino as well as up the
northern Sacramento Valley are 20 kts out of the south. This
remarkable convergence is adding to the overall lift within the
atmosphere along the front, with almost all of the rain occurring
north of the front.

As a potent upper level shortwave approaches the coast over the
next 12 hours, HiRes models are in good agreement as to a slight
increase in rainfall rates in far northern California over the
next 4 hours or so, followed by a gradual southward drift of the
rainfall plume towards Point Arena and the northern Sacramento
Valley. Rainfall rates may locally increase to as high as 3/4
inches per hour. Along the coast, rates should diminish through
the predawn hours, with the rainfall tapering from north to south
through the morning. Expect 3-6 inches of rain for much of the
northern Sierras through 19Z, 2-4 inches of rain for the northern
Coastal Ranges, and lesser amounts within the Sacramento Valley
along the I-5 corridor and to the immediate lee (east) of the
coastal ranges.

Mudslides and rock slides are possible in the foothills and
mountains below 6,500 feet where the precipitation remains all
rain. Localized flooding is possible in the areas where the
heaviest rain occurs over flood-sensitive and low-lying areas.

Wegman

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5Y4MMwOjNyUN8M1ASjGdGoHdQd6EJBF4AQTmwo1AvwSuAu3qu99oohaY-xe_RHQ_mUMv= 9zgJEkNuqis28DNtP29-2pg$ for graphic product...

ATTN...WFO...EKA...MFR...MTR...REV...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 41902181 41862023 41252007 39932011 39391980=20
38501957 38312007 38352115 39352158 40282212=20
40012270 39472270 38732243 38352235 38622251=20
38122328 38932398 39432394 40012417 40472452=20
40982421 41562316=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 021936
FFGMPD
CAZ000-030700-

Mesoscale Precipitation Discussion 0013
NWS Weather Prediction Center College Park MD
236 PM EST Sun Feb 02 2025

Areas affected...northern California

Concerning...Heavy rainfall

Valid 021935Z - 030700Z

SUMMARY...Moderate to Heavy rain will continue over the northern
Sierra Nevada throughout the next 6-12 hours while a second round
of moderate to locally heavy rain develops for the northern
Coastal Ranges this evening. While locally higher totals will be
possible on an isolated basis, additional rainfall totals of 3 to
5 inches are expected for the northern Sierra Nevada into the
southern Cascades and an additional 1 to 2 inches for the northern
Coastal Ranges through 07Z.

DISCUSSION...Eastern Pacific view of total precipitable water (PW)
showed a relatively narrow axis of values greater than 1 inch
extending from near the triple point of an occluded cyclone 36N
138W (which showed up well in visible satellite imagery), ENE to
the northern CA coast. Gauge observations have shown peak hourly
rainfall totals in the 18Z hour of 0.1 to 0.2 inches for the
northern Coastal Ranges and 0.25 to locally in excess of 0.5 in/hr
for the northern Sierra Nevada. 24 hour totals near 9 inches have
been reported just east of Chico in the Sierra Nevada with up to
roughly 4 inches for the northern Coastal Ranges. Reports of
flooding thus far have been limited and primarily focused across
southern portions of the region on either side of I-80 in the
Sierra Nevada and between San Pablo Bay and Santa Rosa via local
storm reports.

Confluent mid-level flow between a mid-level low over southwestern
Canada and a low amplitude longwave trough centered near 145W
along with a ridge over the Baja Peninsula will keep zonal flow
focused from the northern CA and OR coastline, eastward into the
central U.S. through the overnight. At the surface, a shallow but
well-defined stationary front, co-located with the moisture axis,
will essentially remain in the same place over the next 6-12 hours
(slow northward drift), with low level winds varying within the
plume between 40-50 kt in the 850-700 mb layer. Some subtle
strengthening of 850 mb winds will be possible toward 00Z ahead of
the leading edge of a weak mid-level shortwave expected to near
the West Coast at 00Z, but IVT values are forecast to remain in
the 400-600 kg/m/s range through 06Z Monday across northern CA.

No significant changes to peak rainfall rates are expected for
northern CA through 06Z, but additional light to moderate rainfall
(perhaps locally heavy) is expected into the northern Coastal
Ranges later this evening with the approach of the offshore
mid-level impulse. Additional peak rainfall totals of 1-2 inches
for the Coastal Ranges and 3-5 inches for the northern Sierra
Nevada are likely over the next 12 hours but given rainfall rates
will remain somewhat modest, it is the long duration of this
rainfall event that will be noteworthy. At least through 06Z
tonight, additional flooding impacts are expected to remain
isolated with rainfall rates remaining under more critical
thresholds.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4n3AZcPfTSdqmNWbK_ffJ6tUgbACVgJ7QSgoq4mOymxc8QfMd6TnHX7t1gN3EeZjfQhd= wbRivGG_nTd2zxNA-mPbQZ4$ for graphic product...

ATTN...WFO...EKA...MFR...MTR...REV...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 41932111 41782055 41352037 41122043 40772058=20
40382047 39872026 39282015 38942034 38772068=20
38712095 38892118 39192143 39482163 39782182=20
40032213 40082244 39972271 39512264 39282247=20
38962222 38592215 38302216 38122234 38132269=20
38222311 38502358 38832386 39182406 39592417=20
40192451 40602421 40832377 40892338 40932300=20
41122267 41302234 41712170=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 022304
FFGMPD
CAZ000-030200-

Mesoscale Precipitation Discussion 0014
NWS Weather Prediction Center College Park MD
603 PM EST Sun Feb 02 2025

Areas affected...Shasta County / northern CA

Concerning...Heavy rainfall...Flash flooding likely

Valid 022302Z - 030200Z

SUMMARY...A narrow and focused band of heavy rain is expected to
result in a localized area of flash flooding for portions of
Shasta County in and around the Redding metro area. Peak hourly
rainfall of 1-2 inches will be possible with localized additional
totals of 3-5 inches through 02Z.

DISCUSSION...Local radar imagery from KBBX at 2240Z showed a
narrow band (just 2-4 miles wide) of stationary heavy rain
occurring just south of downtown Redding, CA. This band has been
present for the past 2 to 3 hours and has resulted in 4 to 6
inches of rain, most of which has occurred since 20Z. These
rainfall reports have been sourced from a number of
Wunderground.com observations with the band just recently shifting
south to Redding Regional Airport.

The band of heavy rain was located along an axis of strong
surface/near-surface convergence co-located with a
quasi-stationary front that extended SW to NE across the northern
Sacramento Valley. Weak instability may be present with RAP
estimates of near 100 J/kg. Little change to the pattern on the
regional scale is expected to keep the quasi-stationary front in
roughly the same position over the next few hours though some
minor wavering of the rainfall axis is expected over the next
couple of hours along with possible weakening of the little
instability that could be in place. Given the presence of this
band of heavy rain across the I-5 corridor near Redding and into
the higher terrain of eastern Shasta County, a localized area of
flash flooding appears likely with this band. Due to the highly
mesoscale nature of this feature, confidence is below average in
its longevity but it seems likely to persist for at least another
1-2 hours.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4FAue9RTzh4i5PUpyW3cLxsADkEMcSbETXUz06rF_bbTk_yK60JiUQSPa9-OGZO58C4g= VO04DZVPTarVWNVVISBa5BE$ for graphic product...

ATTN...WFO...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 41082185 40972166 40772163 40642187 40262256=20
40462268 40972208=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 030213
FFGMPD
CAZ000-030700-

Mesoscale Precipitation Discussion 0015
NWS Weather Prediction Center College Park MD
913 PM EST Sun Feb 02 2025

Areas affected...Redding Area of Shasta County

Concerning...Heavy rainfall...Flash flooding possible

Valid 030212Z - 030700Z

SUMMARY...Heavy rain associated with a convergence band over
Shasta County, CA will continue into tonight. Flash flooding will
be possible in addition to the ongoing areal flooding.

DISCUSSION...An impressive WSW-ENE convergence band that set up at
the head of the Sacramento Valley near Redding and Anderson, CA
continues to be the source of heavy rain this evening. A strong
southerly low level jet (LLJ) with winds of over 40 kts at 850 mb
continues along the Sacramento Valley, with surface stations south
of the band reporting winds as high as 20 kts south of the band.
The band had been nearly stationary over Anderson, CA or just
south of Redding, but trends have been for the band to crawl
northward with time. Guidance shows very little if any
instability, so this band is likely being forced by the strong
convergence in the area from the combination of the strong
southerly flow with the LLJ hitting a stationary front in that
same area, as well as localized upslope as the terrain of the
Sacramento Valley forms an arc, or upside down U, allowing for
southerly flow to become focused and converge in the Redding area.
Surface observations show there has been over 1.7 inches of rain
in the last 3 hours, and 2.5 inches of rain in the last 6.

HiRes guidance is in good agreement that the front and convergence
band will remain in place for at least the next several hours, if
not throughout the overnight (HRRR). With rates as high as an inch
per hour possible, expect continued areal flooding and possible
flash flooding in those areas where the convergence band interacts
with the terrain to focus the rain water into narrow streams,
creeks, and channels. Urban areas in and around Redding may also
locally increase the flash flooding threat.

Wegman

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9eS4LoJC5rkLYwpzCDlGSmDkq3NN8Fuul9JOKPgas3J0LLhDLgP0FQpPCjCFg8iwYp73= zgSNm_NPyE4BnVj4BcMxRqs$ for graphic product...

ATTN...WFO...EKA...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 40792205 40692191 40492197 40422224 40402259=20
40332288 40452290 40542276 40662255 40742235=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 030703
FFGMPD
CAZ000-031900-

Mesoscale Precipitation Discussion 0016
NWS Weather Prediction Center College Park MD
202 AM EST Mon Feb 03 2025

Areas affected...Northern California

Concerning...Heavy rainfall...Flash flooding possible

Valid 030702Z - 031900Z

SUMMARY...Steady rain will continue into northern California today
with localized convergence bands of heavy rain embedded within the
broader atmospheric river. Localized rates over 1 inch per hour
and flash flooding possible.


DISCUSSION...Heavy rain associated with the ongoing atmospheric
river will continue through the day today. Just in the past 24
hours, rainfall amounts locally exceeding 6 inches have fallen
around and just south of the Redding area. This caused flooding in
several areas as noted by the local storm reports. For now the
band that caused that flooding around Redding has diminished in
intensity. However, many of the ingredients that led to the band's
formation remain in place. A stationary front remains in the area
acting as a convergence boundary between the colder air to its
north and the warmer air and southerly flow to its south. A
southerly low level jet from 850 to the surface remains strong
moving up the Sacramento Valley, with winds to 40 kts at 850 and
20 kts as noted by several stations in the Sacramento Valley south
of the area of rain. This low level jet and the orientation of the
terrain are locally enhancing convergence at the northern end of
the Sacramento Valley around Redding, as noted by localized
increased in the radar reflectivities around that area. Meanwhile,
plumes of moisture continue to move into the northern California
coast, where their initial uplift by the northern coastal ranges
are also responsible for heavier rains.

The jet stream remains largely zonal extending hundreds of miles
west out into the Pacific. The upper low to the north and the high
to the south continue to put the squeeze on the moisture plume,
increasing upper level winds and narrowing the moisture into a
100-200 mile wide corridor that is the atmospheric river. During
the day today, the upper low helping direct the jet stream will
retrograde west. This will begin to reorient the atmospheric river
from its current westerly flow to a southwesterly flow. This will
allow the atmospheric river to begin to drift southward down the
coast, while remaining in place over much of interior northern
California. This reorientation may also work to support the low
level jet, as the wind flow becomes more parallel with the
mountains.

HiRes guidance is in agreement that rainfall rates should remain
largely steady through the early morning, though again embedded
heavier bands remain very possible, especially at the northern end
of the Sacramento Valley. Where any bands form, localized flash
flooding in addition to the ongoing areal flooding cannot be ruled
out. A subtle surface low will approach the coast around 18Z,
likely enhancing the rainfall rates area-wide from west to east
and could cause additional flooding into the afternoon. Expect
another 2-4 inches of rain into the northern Sacramento Valley
through 19Z with 1-3 inches of rain expected elsewhere in the
highlighted area.

Wegman

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7nIjQKs2tSVxxpcQYGLU-voXabZlkuB003nbt11vwnS7sz9ePTpazwWKCbA1blSCz4CG= gVYQhD9XiSdz8mYMgIlR4qQ$ for graphic product...

ATTN...WFO...EKA...MFR...REV...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 41912071 41622024 41282032 40912043 40342055=20
39872043 39302035 39182094 39862145 40172184=20
40302233 39802263 39442263 39162262 38912281=20
38832334 38902386 39432391 39712388 40082424=20
40392454 40732441 41102419 41622357 41882317=20
41852176=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 031757
FFGMPD
CAZ000-040600-

Mesoscale Precipitation Discussion 0017
NWS Weather Prediction Center College Park MD
1256 PM EST Mon Feb 03 2025

Areas affected...Northern California & San Francisco Bay Area...

Concerning...Heavy rainfall

Valid 031800Z - 040600Z

SUMMARY...AR continues though orientation will become more NE-SW
with time as weak height-falls and shortwave press slow moving
cold front southwest toward the Redwood Coast of California and
increasing rainfall potential with some embedded convective
elements possible with hourly rates of .33-.5".

DISCUSSION...18z surface analysis depicts an atypically well
defined surface front across NW NV into the northern portions of
the CA Sierra Nevada into the southern slopes of the Trinity
mountain and toward a weak surface wave near Cape Mendocino.=20
Strong southerly veering to southwesterly flow through the
northern Valley continues to intersect and ascend with moderate
moisture into the upper 40s/lower 50s in Tds. Cold air into SW OR
allows for a fairly steep isentropic ascent pattern to maintain
light to moderate rainfall across the rim of mountains across the
northern Valley with snow levels still above most but the highest
peaks of the terrain. As such, prolonged .15-.25"/hr rates are
likely to continue for a few more hours before the orientation of
the AR/plume changes with the advance of the front; generally with
a fulcrum/pivot point of the plume centered in N CA near
Shasta/Siskyou county line.

GOES-W IR and WV suite show a defined shortwave comma
east-southeast of the 40N130W benchmark continuing to advance
rapidly northeast under the influence of the rapidly exiting 150kt
jet streak and associated right entrance region. As the
ascent/shortwave-ridge pattern passes with this entrance region,
influence of surface to 850mb northwesterly flow will allow for
eastward progression of the well defined frontal zone. CIRA LPW
sfc-850mb layer shows the stark moisture difference across the
boundary with solid .5" over-topped by .25-.3" at 850-700mb and
further solid core of subtropical moisture already at 700-500mb along/downstream of the shearing shortwave to further increase
total moisture to over 1" nearing 1.25" intersecting the Redwood
Coast southeast of Cape Mendocino. The shortwave is expected to
further elongate/shear while reaching the NW CA coast by 00-02z
period and the associated cold front intersection with the coast
will drop southeastward. Forty-five to 60 degrees of sfc-850
25-35kt confluent flow will support IVT to increase slowly from
300-400 to 400-600 kg/m/s as the core of deepest moisture overlaps
after 00-06z. Some mid-level CAA may support very weak vertical
development given 50-150 J/kg possible; though driving mechanism
is likely to be more low level convergence and orographic ascent
across the Coastal Range. Typical .25-.33"/hr may occasionally
increase to .5"/hr across S Mendocino county into Sonoma county
after 00z. Scattered showers may extend into the Bay and Santa
Cruz mountains late in the period (03-06z), though rates are not
likely to be sizable for any flash flooding with exception of most
susceptible urban locations.

...Northern Valley/Lower Slopes of Sierra Nevada...
Southerly flow will veer to more southwesterly and increase
orographic ascent toward perpendicular as the shortwave/DPVA
crosses the region after 00z. Solid remaining moisture in the
valley will ascent and present solid potential for .25-.5"/hr
rates resulting in spotty totals of 2-2.5" by 06z. Given recent
heavy rainfall and increased upper soil saturation increased
run-off will occur resulting in areal expansion of increased
riverine stream flows.

All locales and rates are likely to be below critical values for
any flashy style flooding and so will keep the tag on this
discussion at Heavy Rainfall but will continue to monitor for any
highly localized issues that may unfold.=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5NT9hdA1JDhaj4Y1NVc-AQ5Osz_eKHK8Hq3u18ZgRFhg6FFoR-LJP0Siff8Lgcpr-N_u= S4j1gv4W9wxECn3Yf4sNI44$ for graphic product...

ATTN...WFO...EKA...MFR...MTR...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 41412218 41392159 41082138 40842145 40682170=20
40402166 40062151 39822115 39602081 39192055=20
38772036 38372059 38532160 38292196 37802207=20
37182183 36892198 36952237 37972305 38442344=20
38962384 39722393 40052434 40502446 40972405=20
40732365 40942346 40832288 41112243=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 041813
FFGMPD
CAZ000-050600-

Mesoscale Precipitation Discussion 0019
NWS Weather Prediction Center College Park MD
111 PM EST Tue Feb 04 2025

Areas affected...Northern and Central California

Concerning...Heavy rainfall...Flash flooding possible

Valid 041800Z - 050600Z

Summary...Localized flash flooding is possible with additional
1-3"+ rainfall totals through 06z. Localities most likely to
realize isolated flash flooding from additional 3-5" totals are
along the northern foothills of the Sierras and the Santa Lucia
Range.

Discussion...Another round of moderate to heavy precipitation is
underway across portions of northern and central CA, driven by a
mid-level vort max leading an anomalous shortwave trough pivoting
into the Pacific Northwest (along with synoptic uplift provided by
upper-level divergence via the left exit region of a 130+ kt jet
streak). The 12z HREF indicates an additional 1-3"+ of QPF through
06z, with localities along the northern foothills of the Sierras
and the Santa Lucia Range most at risk of localized flash flooding
(with the highest chances for 0.5"+/hr rates and additional totals
of 3-5", per the 12z HREF 40-km neighborhood probabilities for
0.5" exceedance and ensemble agreement scale 0-100 km of 3.0"
exceedance, respectively). The HRRR has also been among some of
the wettest guidance, suggesting banded rainfall capable of
0.5-1.0"/hr rainfall rates extending into the lower elevations of
coastal regions (such as Santa Rosa and San Francisco). This seems
plausible, given the location of the surface boundary and the
uptick in low-level moisture flux convergence already underway per
SPC RAP analysis (along with the favorable synoptic environment
and total precipitable water values of 1.2"+ near the max moving
average, per OAK sounding climatology). Please consult local NWS
products for up-to-date information on flood hazards.

Churchill

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-3MqJeUTsCEduFm2c40d3KhB_DpG4USTTrHVrqWRBE724la5up9LZmQrMY6CbeVvHZIQ= fGwsoLslMkDywPsQgzK1dI4$ for graphic product...

ATTN...WFO...EKA...HNX...LOX...MFR...MTR...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 41232226 41182197 40922182 40512171 40212157=20
39972125 39732092 39032065 38462016 37751965=20
37391947 36991909 36571882 36321867 36041878=20
36251903 36631941 36891963 37191985 37412019=20
37602049 37522078 37372103 37082126 36702152=20
36472146 36212119 35892084 35482062 35302078=20
35362137 35772195 36402232 37162279 37802305=20
38442338 38742315 39122321 39412339 39792365=20
40072361 40452342 40812310 40972275 41122236=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 060557
FFGMPD
MDZ000-VAZ000-WVZ000-OHZ000-KYZ000-061154-

Mesoscale Precipitation Discussion 0020
NWS Weather Prediction Center College Park MD
1256 AM EST Thu Feb 06 2025

Areas affected...much of West Virginia, far northeastern Kentucky

Concerning...Heavy rainfall...Flash flooding possible

Valid 060554Z - 061154Z

Summary...A gradual uptick in excessive runoff potential is
expected especially in central/eastern West Virginia through 12Z.
Local 1-2 inch rainfall totals are expected.

Discussion...Areas of light to moderate rainfall have developed
across much of the discussion area since 03Z, with several
observations of 0.5-1 inch rainfall totals noted. In addition to
the recent rainfall, an upstream scenario is favoring repeated
rainfall with heavier rates through 12Z, including: 1) upstream
shortwave energy encouraging updrafts across western KY/TN, 2)
increasing low-level flow impinging on a low-level boundary
near/along the KY/TN border, and 3) 40-60 knot low-level flow,
which was increasing instability/MUCAPE from west to east across
Kentucky and vicinity. The net result of this pattern is a
gradual increase in convective elements along a west-east axis
from western Kentucky through the discussion area. Nearly
continuous rainfall should occur through 12Z in most areas, with
spots of 0.25-0.5 inch/hr rain rates and 1-2 inch rainfall totals
expected.

These rainfall totals should fall across areas of wet soils from
antecedent rainfall over the past month from eastern KY into the
central Appalachians. FFG thresholds are generally in the 1
inch/3-hour range and are potentially lowering given ongoing
rainfall. The regime should support a few areas of
runoff/flooding especially across sensitive terrain in
central/eastern West Virginia.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8u5tbUgiwIZheyNTPlzDMifhCAMlBdj6Hb5O6QBIEXw_tPWEV3CBwUTr2jl5tQFtN51T= MZwco3xcbOTNj646mYFQZLk$ for graphic product...

ATTN...WFO...ILN...JKL...LWX...PBZ...RLX...RNK...

ATTN...RFC...MARFC...OHRFC...NWC...

LAT...LON 39377916 39007889 38137978 37548077 37458241=20
37928337 38258350 38538317 38878224 39208068=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 060822
FFGMPD
WVZ000-OHZ000-KYZ000-061321-

Mesoscale Precipitation Discussion 0021
NWS Weather Prediction Center College Park MD
322 AM EST Thu Feb 06 2025

Areas affected...northern/central Kentucky

Concerning...Heavy rainfall...Flash flooding possible

Valid 060821Z - 061321Z

Summary...At least minor/isolated flash flood potential should
continue through 13Z or so as upstream convection near the
Mississippi/Ohio River confluence migrates eastward through the
discussion area.

Discussion...Persistent, repeating convection along an axis from
near Lexington, KY to near Huntington, WV has produced several
areas of 1-1.75 inch rainfall totals over the past 3-6 hours
despite relatively quick movement. The rainfall associated with
these storms has wet soils considerably across the region, with
most recently updated FFG thresholds lowering into the 0.25-0.75
inch/hr range and MRMS Flash responses suggestive of at least
isolated, minor flooding and runoff issues existing along that
corridor.

Convection upstream of this region is causing some concern that
perhaps another uptick in flash flood potential might occur
between 09-13Z. This convection is expected to expand due to 1)
forcing for ascent aloft associated with mid-level vort maxima
across IL/IN, 2) fast low-level flow impinging on a warm front in
western KY, and 3) increasing MU/SBCAPE across the region. CAMs
generally follow suit with this thinking, suggesting another round
of potential training convection entering the Lexington/Huntington
axis between 10-13Z with possible 0.25-0.75 inch/hr rain rates.=20

Should this potential materialize as forecast, isolated flash
flood potential can be expected especially in the 10-13Z timeframe.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8Dbq6sRFf-TmWAgKxEN9tpF57_2A46cfFrfpBZfR6GDUtFhpx-71Wt25V371NY16Y7ly= aHQuREIgM8AVbkSlD_tx01g$ for graphic product...

ATTN...WFO...ILN...JKL...LMK...RLX...

ATTN...RFC...OHRFC...NWC...

LAT...LON 38728286 37988244 37468285 37208508 37498620=20
38138567 38578468=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 061300
FFGMPD
VAZ000-WVZ000-KYZ000-061830-

Mesoscale Precipitation Discussion 0022
NWS Weather Prediction Center College Park MD
800 AM EST Thu Feb 06 2025

Areas affected...South-central & Eastern KY...Southern WV... Far
Western VA...

Concerning...Heavy rainfall...Flash flooding possible

Valid 061300Z - 061830Z

SUMMARY...While intensity and coverage is on a downward trend, a
few cells will remain capable of intense rain rates of
1.25-1.5"/hr over saturated soils for scattered incident or two of
flash flooding through the remainder of the morning.

DISCUSSION...GOES-E WV suite shows the core of the triggering
shortwave energy along the base of the broader synoptic trough has
slid across central Ohio with trailing tail crossing northern KY
along/ahead of the approaching 130+kt flat upper-level jet. This
orientation continues to provide solid broad scale ascent with
DPVA south and eastward across the area of concern, accompanied by
solid divergence to maintain ongoing convective activity across
the warm sector. Surface and VAD wind profiles also denote the
speed and directional confluence/convergence supporting the active
line of cells with about 30-45 degrees of convergence in both
10-20kts of sfc and 50 to 60kts of 850mb flow. Additionally, this
confluence zone continues to align with diminishing but
sufficient unstable air mass with mid-60s temps over upper 50s/low
60s Tds and modest lapse rates for 750-1000 J/kg of SBCAPE across
south-central to southeastern KY reducing across WV to below 500
J/kg.

As such, overall trends have been toward slightly warming tops;
however, there remain some stronger/broader updrafts with weak
rotation across southern KY to tap all the available low level
moisture (over 1.25" total PWats), to allow for some remaining
efficient rainfall with sub-hourly rates resulting in some totals
over 1-1.25" in quick duration. Instability and rates will
diminish through the morning, but west to east cell motion and
inflow from the southeast into increasing terrain should help for
some orographic enhancement as well to maintain a low-end
scattered threat for intense rates.=20

While orientation of the convergence/convective line has become
more oblique to the mean steering flow, reducing the capability
for much higher totals from training noted overall; the soil
conditions across E KY into S WV/W VA remain cold and highly
saturated with NASA SPoRT LIS 0-40cm soil ratios well over 75%
with some spots near 90% in higher terrain that may still have or
recently just lost the majority of snow pack. As such, FFG values
are very low (1-1.5"/hr) naturally and with little capacity for
uptake especially in remaining sub-hourly intense rates...even has
they diminish with reducing instability into late morning,
incidents of flash flooding will remain possible.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4QeDRkGcVP3I_A0OHqJcVfoqVaN09OCm6L59ruCauiCi-ZP8B0HE2_GPbwyy0ITJEJdY= XHekTKSHT7OVBkq_Z6OdEhs$ for graphic product...

ATTN...WFO...JKL...LMK...MRX...RLX...RNK...

ATTN...RFC...LMRFC...OHRFC...NWC...

LAT...LON 38778098 38658043 38308041 37908075 37228132=20
36698199 36628406 36738564 37078586 37408487=20
38088309 38468188=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 061444
FFGMPD
CAZ000-070300-

Mesoscale Precipitation Discussion 0023
NWS Weather Prediction Center College Park MD
943 AM EST Thu Feb 06 2025

Areas affected...Coastal Ranges, Sacramento Valley and Lower
Slopes of Sierra Nevada in California

Concerning...Heavy rainfall...Flash flooding possible

Valid 061500Z - 070300Z

SUMMARY...Compact, quick moving storm with anomalous moisture flux
to affect mainly coastal ranges at first but by late afternoon
transition to more convective localized convective showers with
training potential. Given rates up to .5"/hr, locally 2-3" totals
are possible in favored orography.=20

DISCUSSION...GOES-W WV suite denotes a compact, increasingly
well-defined southern stream shortwave and associated surface low
near 38N and 128W lifting east-northeast with expanding baroclinic
shield downstream starting to cover much of northern California.
This wave/low will continue to strengthen and occlude further
throughout the day as northern upstream persistent upper-low
finally swings southeast and provides further DPVA and sharpens
the entrance region to the strengthen upper-level jet streak;
while steepening lapse rates with cold advection aloft (mainly
affecting northern CA later in the forecast period, after 00z),
prolonging the onshore flow and potential for locally heavy
rainfall.

RAP analysis/forecast shows strong warm advective pattern
approaching the central California coast with southerly 30kt 850mb
winds veering to 50-65kts in the 17-19z period. The nose of the
LLJ is also accompanied by the core of a narrow warm
conveyor/moisture axis with 1-1.25" total PWats (though CIRA LPW
suggests this is mainly below 700mb) and trends continue to direct
it centered from Monterey Bay southward along the Santa Lucia
Range. IVT values appear to be 600-700 kg/m/s and given
orthogonal ascent to the southern Santa Cruz and Santa Lucia
range, rates of .33-.5"/hr are likely to commence with the arrival
of the warm front around 17-18z and continue for 5-6hrs, with a
very slow southward drift of the core of the LLJ/moisture axis.=20
This magnitude of moisture flux is about 5 standard anomaly above
normal even in the wet season. As such, localized totals of 2-3"+
are probable along the range. Later in the afternoon, the plume of
moisture sags south and rounds Cape Conception around 00z, winds
will slowly be diminishing to about 30kts at 850mb; there is some
more oblique (45-60 degrees) of orographic ascent in the
mid-levels, but southerly surface flow will not increase until
after the forecast period as the cold front rounds the bend. So
at this time there is mixed signals to potential for sizable rates
over the fresh burn scars across the eastern Transverse Ranges, so
while not completely improbable for flash flooding/mudslides by
03z, we will be monitoring closely for potential for a targeted
MPD if conditions increase/warrant it later into this
evening/overnight.

Meanwhile, further north the western branch of the TROWAL will
provide ample moisture flux wrapping north of over the
surface-850mb low to feed surface upslope forcing to allow for
moderate rainfall with .25-.33" rates along the coastal ranges
north of the San Francisco Bay; which should slowly expand
eastward through into the lower slopes of the Trinity to northern
Sierra Nevada Ranges. As the upper-level northern stream DPVA
swings southeast, providing some cooling aloft and steepening
lapse rates, it will also help to sharpen the
deformation/convergence zone across NW CA as the surface low
transitions from coastal to northern central Valley from 23-01z.
An uptick in convective activity with slight reduction in forward
speed may result in spotty .33-.5"/hr rates across the
Redwood/Lost Coast resulting in localized totals of 2-3" by 03z as
well, this should remain more of a heavy rainfall risk as the
older burn scars are less susceptible, but an isolated
creek/stream with quick rise is not completely out of the picture
given soil conditions remain above average in the 80-95
percentiles even for this time of year given recent rainfall.=20

Bottom-line, this quick hitting/strong moisture flux is highly
anomalous even in the wet season but the overall rates and totals
still generally remain below flash flooding concerns and will hold
with a 'heavy rainfall' tag at this time; however will convective
trends closely for any potential targeted MPDs and flash flooding conditions.=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_m8IGq-VPPGXEQyevjqhrrzrpAKV7GP0muBc3Y085SJcZwXQPsBVIx3odYIwSQaiWOVe= yRxGb-5-ycijb610wIr1vsI$ for graphic product...

ATTN...WFO...EKA...HNX...LOX...MTR...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 40862210 40712184 40432167 40082152 39602087=20
39172059 38832038 38522027 38141999 37601966=20
37271940 36881906 36511880 36191865 35951876=20
36131904 36361928 36671951 37201977 37752022=20
38092079 37922118 37852141 37492161 37032143=20
36472092 35972040 35722025 34981988 34761927=20
34551873 34071906 34331984 34422053 34812083=20
35452118 36102182 37532286 38292338 39092396=20
39782422 40382392 40422342 40172319 39972297=20
39912271 40212264 40582251 40842237=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 090206
FFGMPD
VAZ000-WVZ000-OHZ000-KYZ000-090804-

Mesoscale Precipitation Discussion 0028
NWS Weather Prediction Center College Park MD
906 PM EST Sat Feb 08 2025

Areas affected...southern West Virginia, far eastern Kentucky

Concerning...Heavy rainfall...Flash flooding possible

Valid 090204Z - 090804Z

Summary...Fast-moving showers could produce a quick 0.25 inch of
rainfall across the discussion area through 05-06Z. Extremely
sensitive ground conditions suggest potential for
efficient/excessive runoff and impacts during this timeframe.

Discussion...Forcing/ascent along and ahead of a cold front has
aided in development of a couple bands of convection extending
from Parkersburg to Huntington to Somerset, KY. These showers
were in a marginal environment in terms of instability, although
~100 J/kg MUCAPE appears to support updrafts along and ahead of
the front. Quick movement (from 70 kt mean steering flow) has
limited rain rates so far, although recent MRMS data suggests
pockets of 0.1-0.2 inch/hr rates near Jackson, KY over the past
hour.

These showers will move toward portions of the discussion area
that are extremely sensitive to any additional rainfall. NASA
SPORT soil moisture values are near 100% across the area amid
plenty of antecedent rainfall (including 1-1.5 inch totals in the
past 24 hours). FFG thresholds generally range from 0.25-0.5
inch/hr, but are near zero in a few spots. Several impacts were
also reported this from this morning's round of rainfall.=20
Incoming rainfall along/ahead of the front may result in an uptick
in excessive runoff and flood potential through 07Z.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6CEl1e3dRVBZoJxLJsa61bKoSMJFD78rTxWcNS0IlUX6QYExwTPlGoyKjjoYiqi6dcik= Vqkxvao6vBmbl3PUftyaBpo$ for graphic product...

ATTN...WFO...JKL...LWX...PBZ...RLX...RNK...

ATTN...RFC...MARFC...OHRFC...NWC...

LAT...LON 39258120 39198015 38957938 38497951 37768007=20
37438073 37308138 37478217 38198265 38988194=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 131726
FFGMPD
CAZ000-140300-

Mesoscale Precipitation Discussion 0035
NWS Weather Prediction Center College Park MD
1225 PM EST Thu Feb 13 2025

Areas affected...Coastal Central and Southern
California...Foothills of Sierra Nevada...

Concerning...Heavy rainfall...Flash flooding likely

Valid 131730Z - 140300Z

SUMMARY...Strong Cyclone and atypically broad Atmospheric River
will have potential for .75"/hr rates and localized totals of 3-5"
in favored orographic ascent. Flash flooding is likely, especially
in lower FFG of Southern California. Significant flash flooding
may be possible in/near fresh burn scars.=20

DISCUSSION...GOES-W WV suite depicts a broad, fairly symmetric
closed low just off the NW coast of California continuing to bowl
ESE likely crossing the coastline much later tonight. This low is
atypically deep with the 90th to 95th percentile, but in
combination with fairly cold/stronger ridging downstream has
resulted in an atypically broad subtropical moisture plume with
1.25-1.5" total PWat values along upstream along/ahead of the
height-falls and associated cold front. GOES-W Vis/IR suite
denotes a stark cloud line with slightly anafrontal to the
southeastward cold front and moisture surge. Within the thick
stratus plume, 850-700mb flow is in the 50-65kt range and is
currently orthogonal to the Santa Lucia and Diablo Ranges,
presenting strong IVT/orographic convergence along the range.

...Central California/Sierra Nevada Foothills...
The IVT values are 4-5 standard anomaly units above seasonal
average and range about 700-900 kg/m/s. Rates have been slowly
increasing, with 3hr totals reaching 1-1.25" but will likely
increase with an additional .5-.75"/hr for maybe 1-2 hours as the
plume shifts southeastward. Totals already have reached 3-4" in
the Santa Cruz and northern Santa Lucia resulting in rapid stream
rises and some localized reports of flash flooding. The
additional 2-3" over the next few hours will likely result in
spots of 4-6" totals and continue the flash flooding risk.=20=20

Additionally, the plume has saturated the sub-cloud environment in
the San Joaquin Valley to allow for rain to reach the ground as
the core of the plume presses onshore. The warm front will press
through to the foothills and help to increased the depth of
orographic ascent resulting in spots of .75-1"/hr rates before
becoming very heavy snow at or above 7000Kft. This will decrease
with the passage of the plume/cold front and the flux will reduce
accordingly resulting in scattered shallow convective cells and
bands may aggravate the area given those steepening lapse rates,
which may have intense but brief cores of heavy rainfall/small
hail/graupel.

...Southern California...
Unlike further north, there is precedent moist airmass in place
across the California Bight/Channel Islands, surface to 700mb
values are above normal and total PWats are in the 1-1.25" range.
Currently, the warm front has progressed through the highest
terrain of the Transverse Range and winds are veering slightly
while increasing. This will allow for short-term increase in
orographic ascent across the Transverse (particularly east) and
Peninsular Ranges prior the main core of the AR/cold front later
this evening. Rates of .25-.33"/hr will increase as winds slowly
uptick from 15-20 to 30kts by 00z below 7500 Kft across the
ranges. Spots of 1-1.5" are probable to pre-soak the windward
facing topography.=20=20

A few hours prior to 00z, the cold front and AR will round Cape
Conception and winds will have solid veered profile with depth
with 40-50kts of 850-700mb flow fairly orthogonal to the range. A
few hi-Res CAMs suggest 100-250 J/kg may be present from slightly
higher theta-E air in place allowing for a subtle but important
uptick in vertical development that should result in .75"/hr rates
with spotty potential of 1"/hr. The growing concern here, is
while the plume is less orthogonal to the terrain the breadth of
the AR will allow for increased duration of exposure to the higher
flux. As such, below freezing levels, spots of 3-4" are probable
across the western Transverse Range by 03z and likely to be
similar toward the eastern and Peninsular Ranges thereafter. It
is not out of the realm of possibility that spots of 5" are
possible and heavy rainfall will extend to the coast with .5"/hr
rates and totals over 1-1.5" resulting likely flash flooding
conditions through the evening even for urban locations.=20=20

This is of particular concern given recent burn scars are going to
be less tolerable to any rates over .50"/hr let alone any
potential crossings of .75-1"/hr. It is too early to be certain
about any particular canyon/scar, but given hourly rates and
overall totals there is a sizable possibility for significant
flash flooding/debris flows in or near these scars and avoidance
of this prone areas is strongly advised. Please keep close
attention to local statements/warnings from WFO Los Angeles, state
and local emergency managers. It is possible a subsequent
targeted MPD may be required to address ongoing rainfall trends.=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5Jo-Vnr9C7RceznyxJQj2mzaqf1eMMqjQu8gci3RUa33MtzZyNzLc3-bkHz0P8kSr9kP= RHKQXeh5NFj5hCkzyP5N6vM$ for graphic product...

ATTN...WFO...HNX...LOX...MTR...SGX...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 39472072 39042072 38382025 37511965 37171934=20
36811897 36291868 35631855 35491870 35611899=20
36381942 37042017 37252083 36982108 36442068=20
35832027 35381997 35141959 34871927 34721872=20
34681829 34651797 34351744 34271688 33721646=20
33041646 32571633 32541676 32521721 32761767=20
32821887 33141955 33592012 34292057 35002087=20
35632142 35912176 37062251 37762270 38112257=20
38602206 39002160 39242125=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 140217
FFGMPD
CAZ000-141200-

Mesoscale Precipitation Discussion 0036
NWS Weather Prediction Center College Park MD
916 PM EST Thu Feb 13 2025

Areas affected...Coastal Southern California...Foothills of the
SIerra

Concerning...Heavy rainfall...Flash flooding likely

Valid 140200Z - 141200Z

SUMMARY...The ongoing Atmospheric River event will continue into
the early hours of Saturday, with the threat of .50-.75"+ hourly
rainfall rates across portions of Southern California and into the
western upslope of the Sierra. Flash flooding will remain likely
across Southern California, especially across recent burn scar
areas, and possible in the foothills of the Sierra. The flash
flooding threat will be diminishing from west to east across
Southern California after 0200 UTC as a cold front moves steadily
east, but should perist to near 1200 UTC in the Sierra Foothills.

DISCUSSION...The latest GOES-W satellite imagery shows the broad
mid to upper level trof along the west coast pushing steadily
inland. An axis of anomalous PW values..2 to 2.5+ standard
deviations above the mean, and 850-700 mb moisture flux anomalies
of 3 to 5+ standard deviations above the mean, will continue on
the southeast side of this upper trof, along and ahead of the
associated cold front pushing steadily eastward across Southern
California this evening. Surface analysis at 0000 UTC indicates
this front having pushed to the southeast of Santa Barbara and
extending eastward just south of Sandburg and Edwards AFB.=20=20=20
There is good consensus in the latest hi res guidance on the
timing of the primary heavy rain areas in the vicinity of this=20
front pushing across Southern California this evening. HREF
neighborhood probabilities are high, 90%+, for hourly rain totals
of .50"+/hr along and ahead of the front, but drop to generally
less than 25% for 1"+/hr, reflective of the progressive nature of
this front. This progression will lead to a sharp cutoff in the
flash flood threat as the front passes. However, until this
occurs, flash flooding will remain likely across Southern
California, especially over recent burn scar regions.=20

..Foothills of the Sierra Nevada...
While the primary anomalous PW axis will remain across Southern
California this evening, persistent west southwesterly low level
upslope flow level will continue to impact the foothills of the
Sierra into early Saturday. HREF neighborhood probabilities for
.50"+/hr rainfall amounts are not as high or continuous as areas
across Southern California. but do depict potential for localized
heavy amounts and the potential for flash flooding issues.=20
Simulated hi res radars do show potential for cells to be much
slower moving and train in the upslope regions of the Sierra. In
areas of training, additional hourly amounts of .50-.75"+ and
additional totals of 2-3" are possible through early Saturday
morning.
=20

Oravec

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!89MFGru-sN9tQMcyudE5FAOdDpRlLChT9anMRUAZeQHCenuXZAVsnylGh7z6d0rV3Mh9= Cq58UMkl4T356xrp3V4SigM$ for graphic product...

ATTN...WFO...HNX...LOX...PSR...SGX...STO...VEF...

ATTN...RFC...CNRFC...NWC...

LAT...LON 39932145 39242074 38191983 38101991 37181925=20
36221856 35051825 34711787 34711774 34451696=20
34351684 33951639 32951616 32321669 33011746=20
33041754 33101769 33441803 33491825 33951871=20
34411857 35511890 36741990 37352017 38572095=20
39722147=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 130221
FFGMPD
NCZ000-GAZ000-TNZ000-ALZ000-MSZ000-LAZ000-130820-

Mesoscale Precipitation Discussion 0032
NWS Weather Prediction Center College Park MD
920 PM EST Wed Feb 12 2025

Areas affected...Portions of Eastern LA...Southern MS...Much of
AL...Southeast TN...Northern GA

Concerning...Heavy rainfall...Flash flooding likely

Valid 130220Z - 130820Z

SUMMARY...Heavy showers and thunderstorms will continue to impact
the South overnight with concerns for high rainfall rates and
cell-training. Additional areas of flash flooding are likely which
will include the more sensitive urban corridors.

DISCUSSION...The latest radar and satellite imagery continues to
show a well-organized convective outbreak evolving across the
South with multiple bands of strong to severe convection,
including supercells, that are focusing corridors of locally
enhanced rainfall. A strong southwest low-level jet of 40 to 50+
kts continues to advance up across eastern LA through southern MS,
with it nosing up into areas of western and central AL. This is
fostering strong moisture transport along with the arrival of a
moderately buoyant airmass characterized by MUCAPE values of 1000
to 2000 J/kg.

Strong low to mid-level veering flow with height continues to
yield enhanced shear profiles favorable for supercells and these
more organized storms out ahead of an approaching cold front and
in vicinity of a warm front lifting northeast across the Southeast
have been tending to locally train over the same location this
evening.

Over the next few hours, areas of southern MS through central AL
in particular will continue to see cell-training and cell-merger
concerns as the convection attempts to evolve a bit more into a
QLCS which will still include embedded supercell concerns. By late
this evening and going well past midnight, areas of northwest GA
will begin to see more of the concentration of heavier convective
rainfall.

The evening CAM guidance, including the HRRR and the experimental
WoFS supports an additional 2 to 4 inches of rain with isolated
heavier amounts possible where the corridors of more organized
cell-training occurs, and this will be aided by rainfall rates of
generally 1 to 2+ inches/hour.

Some areas of flash flooding are already occurring, and the
additional rains over the next several hours should yield
additional areas of flash flooding. This will include especially
the more sensitive urban areas, which by later in the night may
include the Atlanta metropolitan area.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_3fNJtQJjYRscRkNcMOzrGhXFAUr56rJ10qzqoCtWZNkR97j4WNaN_fsQhuz9NB-qHqL= UURXVMq2s7XddsY3-NVIKYs$ for graphic product...

ATTN...WFO...BMX...FFC...GSP...HUN...JAN...LIX...MOB...MRX...

ATTN...RFC...LMRFC...SERFC...NWC...

LAT...LON 35448488 35208370 34498325 33368365 31778605=20
30328893 29919032 30629034 32228877 33658741=20
34978636=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 062159
FFGMPD
VAZ000-WVZ000-TNZ000-KYZ000-INZ000-070357-

Mesoscale Precipitation Discussion 0024
NWS Weather Prediction Center College Park MD
458 PM EST Thu Feb 06 2025

Areas affected...portions of KY and southwest VA

Concerning...Heavy rainfall...Flash flooding possible

Valid 062157Z - 070357Z

Summary...Showers and thunderstorms within a saturated atmospheric
column over saturated soils are expected to lead to hourly rain
totals to 1.5" and local amounts to 3". This could lead to flash
flooding over saturated soils and urban areas.

Discussion...Recent radar imagery shows quick-moving but scattered
showers and thunderstorms forming and moving through western KY at
the present time. They are elevated in nature and forming on the
back side of a frontal zone with a few surface waves on the south
side of a broad shortwave trough in the Great Lakes, utilizing
500-1000 J/kg of MU CAPE. Other activity to the southeast is much
closer to the surface front. At the moment, the flat wave in
western TN is closest to the back edge of the convection.=20
Precipitable water values of 0.75-1.25" lie across the region
within a cool air mass, leading to almost complete saturation.=20
Effective bulk shear is ~50 kts, which is enough for both linear
convective organization and mesocyclone formation.

Flash flood guidance values are fairly low, roughly 1" in three
hours -- within the past 24 hours, 1-3" of rain fell in this area.
With the expectation of 0.5"+ an hour totals, possibly as high as
1.5" in an hour, expected over the next several hours as the
storms propagate generally east-southeast parallel to thickness
lines, flash flood guidance exceedance could occur in scattered
spots where cells can train/two or more mesocyclones can align.=20
The progressive frontal boundary and quick cell movement should
keep rain amounts from getting exceptionally high. Hourly totals
to 1.5" with local amounts to 3" are the expectation, which could
lead to flash flooding in urban areas and over saturated soils and
hilly topography.

Roth

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4hjqNsAz6I_CgvsCe2AdIOO_gfHq22emXLJFkkxZcrzBwWbHk8xyOFB25QZTRoWSnQ43= PyYx9RdN4MljM43fwdPmtzI$ for graphic product...

ATTN...WFO...JKL...LMK...MRX...OHX...PAH...RLX...RNK...

ATTN...RFC...LMRFC...OHRFC...NWC...

LAT...LON 38228453 37108114 36598259 36368416 36528789=20
38218643=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 122031
FFGMPD
ALZ000-MSZ000-LAZ000-130215-

Mesoscale Precipitation Discussion 0031...Corrected
NWS Weather Prediction Center College Park MD
331 PM EST Wed Feb 12 2025

Corrected for updated graphic

Areas affected...Lower Mississippi Valley through Northern Alabama

Concerning...Heavy rainfall...Flash flooding possible

Valid 122024Z - 130215Z

Summary...Showers and thunderstorms rapidly blossoming within a
warm sector will expand in coverage and intensify through the
afternoon. These thunderstorms will lift northward and then train
SW to NE ahead of a cold front, with rainfall rates as much as
2-3"/hr. This could lead to instances of flash flooding.

Discussion...The regional radar mosaic across the Gulf Coast this
afternoon depicts rapidly expanding and intensifying thunderstorms
along and just south of a warm front from LA to the FL Panhandle.
This convection is expanding within a pronounced warm sector
characterized by favorable instability (MLCAPE 1000-2000 J/kg) and
elevated PWs (1.6 to 1.8 inches) according to the SPC
mesoanalysis. Additionally, recent VWPs from the region indicate
modest low-level veering but with strong inflow, supporting large
updrafts capable of producing intense rainfall rates. This is
being analyzed by recent MRMS 15-min rainfall as high as 0.75"
(3"/hr rates), resulting in rising CREST unit streamflow values
across parts of LA and MS. Upstream of this fresh convection, a
wave of low pressure and attendant cold front are analyzed by WPC
crossing from TX into LA, along which additional thunderstorms are
occurring with current FFWs.

As the afternoon progresses into the evening, the environment
should become increasingly unstable as the plume of 1000-2000 J/kg
MLCAPE surges as far north as Birmingham, concurrent with elevated
PWs being drawn northward. This plume of robust thermodynamics
will be advected on 850mb inflow that is progged to reach 50+ kts,
resulting in 850-700mb moisture flux that may exceed 5 sigma
according to the SREF. Additionally, increasing synoptic lift
within the RRQ of an intensifying jet streak will support an
expansion of convection into the evening, with thunderstorms
likely aligning along or just ahead of the convergence axis of the
approaching cold front as it squeezes the warm sector. This
alignment will rapidly enhance the flash flood risk, as training
of cells along the boundary will offset the limiting storm speed
of 40-60kts.

The HREF suggests that coverage of rainfall rates exceeding 1"/hr
will expand, and the HRRR 15-min progs suggest rainfall intensity
may produce 0.75 to 1 inch of rain in as little as 15 minutes.
These rates themselves could cause instances of flash flooding,
but where training occurs, more than 3" of rain is possible,
enhancing the flash flood risk. The most likely locations for any
flash flooding will be across urban areas as soil moisture in
southern LA, MS, AL is drier than normal according to NASA SPoRT.
However, training of these intense rain rates could quickly
overwhelm even the drier soils, so flash flood instances are
possible anywhere across the discussion area into this evening.


Weiss

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5MQOgaXrGVUoKPJkQubelxBuZyrEYS24uHQXIN3l7yhjsj_2rwva_5FCBl-uLT7SYJgF= n5-HZtHsTQA859vPlm0_hRI$ for graphic product...

ATTN...WFO...BMX...HUN...JAN...LCH...LIX...MEG...MOB...SHV...

ATTN...RFC...LMRFC...SERFC...NWC...

LAT...LON 34828712 34538627 33658599 32878613 32308688=20
31708793 31268939 30989077 30979206 30969237=20
31009261 31569255 32349167 34568837=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 070318
FFGMPD
NVZ000-CAZ000-070916-

Mesoscale Precipitation Discussion 0025
NWS Weather Prediction Center College Park MD
1017 PM EST Thu Feb 06 2025

Areas affected...much of California

Concerning...Heavy rainfall...Flash flooding possible

Valid 070316Z - 070916Z

Summary...Flood/flash flood potential should continue on at least
an isolated basis through 09Z/1a PST. An additional 1-2 inches of
rainfall is expected along windward locations of the Sierra, and
locally higher amounts cannot be ruled out.

Discussion...Flood/flash flood potential is expected to continue
through at least 09Z this evening. Persistent lift associated
with an upstream mid-level wave west of Oregon continues to
support scattered to widespread shower activity across the region.
Additionally, strong southerly low-level flow (40-50 knots at
850mb) continues to support local terrain enhancement to rain
rates across windward locations of the Sierra, where hourly rain
rates nearing 0.25 inch were noted per MRMS near/southeast of
Redding. These rates have contributed to isolated flash flooding
and mudslides. This regime is expected to persist for several
more hours, with additional rainfall accumulations of 1-2 inches
expected. Wet (and moistening) ground conditions and ongoing
rainfall is expected to continue to foster at least isolated
instances of excessive runoff/flood impacts.

Around/after 09Z, models suggest the low-level flow enhancing
rainfall rates this evening will begin to weaken slightly.=20
Moderate to heavy rainfall should still remain in the area,
although a gradual decrease in the overall coverage of the
heaviest rainfall should commence. A gradual lessening of the
flash flood risk is also expected during this timeframe.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7sio6R-zD-MkEH7oU-5ZcgLLWkA77ovXv8xNE8-FPjMaKLIzGgMa50aRkvVG02OrovOx= fRjlFcDlzwbRkCjqOCf6qRI$ for graphic product...

ATTN...WFO...EKA...HNX...MFR...MTR...REV...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 41242187 40582099 39452012 38001937 37381921=20
37161927 37201984 38132077 38812152 38512191=20
37612172 36792147 36512163 37682257 40012355=20
40912315 41172265=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 070349
FFGMPD
CAZ000-070948-

Mesoscale Precipitation Discussion 0026
NWS Weather Prediction Center College Park MD
1048 PM EST Thu Feb 06 2025

Areas affected...portions of southern California

Concerning...Heavy rainfall...Flash flooding possible

Valid 070348Z - 070948Z

Summary...Increasing onshore flow is interacting with the
Transverse Ranges in southern California to produce scattered
showers and locally heavy rainfall. Rainfall totals of 0.25-1
inch are possible through 10Z/2am and beyond. Excessive runoff
and debris flows are a distinct possibility - especially near
sensitive areas of variable terrain and near burn scars.=20

Discussion...Over the next several hours, a strong low-level
cyclone (currently centered near Eureka) will migrate
northeastward toward Oregon. As this occurs, strong southwesterly
low-level flow will increase across portions of southern
California especially near terrain-favored coastal ranges. Moist
air (characterized by 1-1.1 inch PW values) will accompany the
increasing flow and become forced over the Transverse Ranges,
resulting in areas of orographically enhanced moderate to heavy
rainfall. This process is already underway, with spots of 0.2-0.4
inch/hr rain rates already observed west of Los Angeles in the
past hour very near Malibu and Castaic. These trends are expected
to continue, and a roughly 6-12 hour window of heavier rainfall
potential will exist across the discussion area continuing into
the overnight hours (perhaps through 12Z-15Z Friday).

These areas of heavy rainfall will occur in areas of sensitivity
from both terrain and burn scars from recent fires across the
region. As a result, areas of flooding and debris flows are
possible. Rainfall totals of 0.25-1 inch are probable through
10Z, with locally higher amounts (exceeding 1.5 inches) possible
in terrain-favored areas.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8xHNefkHYP3_lJgJJICRRL1GK8_LbVx7lSPiJ3pel_wzghsP-I4EeifkSzULBluoOydH= JBQwRntAtlaAIl5l-aQqq0E$ for graphic product...

ATTN...WFO...HNX...LOX...SGX...VEF...

ATTN...RFC...CNRFC...NWC...

LAT...LON 35242052 35241936 35121841 34921756 34291731=20
33971765 34001857 34512041 34842065=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 080741
FFGMPD
VAZ000-WVZ000-OHZ000-KYZ000-081340-

Mesoscale Precipitation Discussion 0027
NWS Weather Prediction Center College Park MD
240 AM EST Sat Feb 08 2025

Areas affected...much of West Virginia and a small part of eastern
Kentucky

Concerning...Heavy rainfall...Flash flooding possible

Valid 080740Z - 081340Z

Summary...At least minor/isolated runoff issues could develop in
the next few hours as moderate rain moves in from central/northern
Kentucky through 14Z.

Discussion...Strong convergence on the nose of a 40-kt low-level
jet over western Kentucky has aided in development of moderate
rainfall generally along an axis from near Louisville to near the
WV/KY border near Pikeville. Within this axis, the persistence of
rainfall has allowed for MRMS-estimated areas of 0.10-0.30 inch/hr
rain rates to materialize. The axis was also parallel to robust
westerly flow aloft (supporting persistence), and recent radar
mosaic imagery indicates upstream shower activity near the MS/OH
River confluence poised to move through areas currently affected
by moderate rainfall. The net result of this pattern is a fairly
prolonged period of light to moderate rainfall eventually
extending into West Virginia, with 0.75-1.25 inch rainfall totals
expected through 14Z across the discussion area.

Despite modest rain rates, soils are wet across the area from
recent rainfall and FFG thresholds are 1) ~0.25 inch/hr and 2)
less than 1 inch/3-hr across parts of the region (especially in
hillier terrain in eastern WV). These thresholds and recent flash
flood events suggest that ground conditions are extremely
sensitive. The moderate rainfall moving in from Kentucky should
persist for several hours, resulting in at least isolated
instances of excessive runoff/flooding. The uptick in flood risk
should persist in the 0830Z-1400Z timeframe and beyond as
low-level convergence strengthens across the area through the day.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_gr4qwKw5K5jYf9hzwSVfd5OU0gHU4AZ65N0702g3mo6SY0OyiHomCv70lD39JquYytq= XuS7c2SyHio4hQsMcSo5XK8$ for graphic product...

ATTN...WFO...ILN...JKL...LWX...PBZ...RLX...RNK...

ATTN...RFC...MARFC...OHRFC...NWC...

LAT...LON 39108015 39037954 38687946 38157973 37708021=20
37518090 37498204 37568309 38528343 38888208=20
38988118=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 130544
FFGMPD
CAZ000-131740-

Mesoscale Precipitation Discussion 0033
NWS Weather Prediction Center College Park MD
1244 AM EST Thu Feb 13 2025

Areas affected...portions of northern, central and southern CA

Concerning...Heavy rainfall...Flash flooding possible

Valid 130543Z - 131740Z

SUMMARY...Areas of heavy rain will overspread a sizable portion of
northern to south-central CA through 18Z Thursday ahead of an
approaching occluded cyclone. Some locations may see hourly
rainfall in excess of 0.5 inches for several hours with the
greatest potential for high rates along the Santa Lucia Range. 12
hour rainfall totals of 3 to 5+ inches are likely within areas of
favored terrain and heavy rain may produce areas of flooding/flash
flooding within urban areas and/or sensitive burn scars.

DISCUSSION...Loops of GOES West water vapor imagery through 05Z
showed a strengthening closed mid to upper-level low centered near
42N 134W. A strong, zonally oriented 250 mb jet axis was located
across 36N 140W, south of the closed low, with winds in excess of
150 kt located as far east as 134W per GOES West DMW vectors. The
location of the upper level jet max west of the upper trough axis
indicated the longwave trough was digging southward, but the
parent closed low appeared to be generally moving toward the east.
A ribbon of moisture streamed from west to east across the eastern
Pacific Ocean along a cold front connected into an occluded
cyclone over the eastern Pacific. TPW and LPW imagery showed that
the plume of moisture extended thousands of miles back to the
west, originating in the tropical west-central Pacific. However,
anomalous moisture was already located just off of the CA coast
with 00Z soundings from OAK and VBG showing PWAT values between
the 90th percentile and climatological max for mid-February. Warm
advection rainfall was already occurring in advance of the warm
front analyzed southeastward toward the south-central CA coast,
roughly 60 miles west of the coast of Monterey County.

As the closed low continues to advance off toward the east over
the next 6-12 hours, the attendant cold front is forecast to
steadily advance east and southeast, reaching the northern coast
of CA around 12Z. IVT values will steadily increase across the
central CA coast through 12Z peaking between 800-900 kg/m/s in the
vicinity of San Francisco. IVT values will remain above 600 kg/m/s
for a good portion of the central to south-central CA coast for
several hours with 850 mb winds peaking between 50-60 kt. The
orientation of the 850 mb flow is expected to be perpendicular to
the coast from North Bay to Point Conception.

Hourly rainfall in excess of 0.5 inches will become likely in and
around the higher terrain of San Francisco Bay by 09Z, perhaps
lasting for 3-5 hours. Farther south, hourly rainfall may reach 1
in/hr along the Santa Lucia Range given the favorable orthogonal
orientation of the low level flow to the axis of the mountain
chain. Downstream into the Sierra Nevada, snow levels are expected
to be near 7000 ft which will result in rainfall impacts to
potentially extend up to a relatively high elevation. Hourly
rainfall in excess of 0.5 inches may exceed 6 hours in duration
for portions of the central Sierra Nevada and Santa Lucia Range.
Sub-hourly rainfall rates over 0.25 inches in 15 minutes will be
possible within area of orographic ascent and boosted by weak
instability, though CAPE values are forecast to remain focused
below ~4 km AGL and stay below 250 J/kg by a majority of the most
recent guidance prior to 18Z.

12 hour rainfall totals through 17/18Z are expected to peak in the
3 to 5 inch range for the Coastal Ranges into the upslope regions
of the central Sierra Nevada, through higher totals may occur
within the Santa Lucia Range given a favorable low level wind
orientation. While flooding/flash flooding will be possible, it is
expected to remain on the low end of the scale and may be focused
across urban areas or perhaps lingering sensitivity on any area
burn scars.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5Xmh9Oowt5YmUjifd4UFwIY0mxZaT2flnAljU8G1GJgFwfOn4sGM2mM1sT_wTJ33SY2v= mCQsmDq9al77Us9izFuTJMQ$ for graphic product...

ATTN...WFO...EKA...HNX...LOX...MTR...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 40782243 40652194 40112164 39712119 39512070=20
39232058 38912037 38572025 38051987 37581950=20
37421919 37171914 37021903 36751880 36571874=20
36271862 35941838 35501850 35381881 36001952=20
36032012 35642002 35171970 34622061 35212158=20
35932251 37862346 39302456 39972518 40592460=20
40532360 40662277=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 130817
FFGMPD
FLZ000-GAZ000-ALZ000-131345-

Mesoscale Precipitation Discussion 0034
NWS Weather Prediction Center College Park MD
317 AM EST Thu Feb 13 2025

Areas affected...FL Panhandle into southeastern AL and central GA

Concerning...Heavy rainfall...Flash flooding possible

Valid 130815Z - 131345Z

SUMMARY...A low probability threat for flash flooding due to
training will exist from the FL Panhandle into southeastern AL and
central GA through ~13Z. The threat will carry the potential for
rainfall rates in the 1-2 in/hr range within any areas of training.

DISCUSSION...Radar imagery at 08Z showed that a SW to NE oriented
axis of thunderstorms extended from the western FL Panhandle into
north-central GA. These thunderstorms were located out ahead of a
cold front and trends over the past few hours have shown a
weakening of the portion of the line over southwestern AL in favor
of strengthening of a new line out ahead, which was currently
crossing the western FL Panhandle. Recent infrared satellite/radar
trends through 08Z showed yet another line beginning to organize
about ahead of the existing convective axis, ~85 miles south of
Mobile Bay.

The environment within the warm sector was characterized by 500 to
1500 J/kg MLCAPE from the warm frontal position along the AL/GA
border to just south of the Gulf Coast along the FL Panhandle.
Flash flood guidance was lowest to the north (2-3 inches in 3
hours) and highest in western FL (4+ inches in 3 hours). The
greatest potential for high rainfall rates, near or even in excess
of 2 in/hr, will exist within the better instability across
southern locations.

Water vapor imagery showed a longwave trough over the central U.S.
advancing east, but with the base of the trough lifting north,
from OK to the MS Valley. This deamplification along the southern
end of the upper trough favors a gradual weakening trend of 850 mb
wind magnitude and of convective intensity over the AL/GA/FL
tri-state region. However, lingering instability and sufficient
low level moisture transport could allow for training if the
convective axis to the south continues to expand north and meets
with the ongoing northern portion advancing to the east at a
somewhat faster pace. While the general movement should be a
progressive eastward movement at 25-30 kt, There is a low end
chance that alignment of the heavy rain axis/axes will allow for a
brief period of training, which could contain rainfall rates of
1-2 in/hr, and local 2-3 inches of rain over a 2 to 3 hour window.
Localized flash flooding could result, but again, this threat
appears to be fairly low and recent CAM guidance does not support
much in the way of a flash flood threat over the next 3-5 hours.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7s8IP4xI0b1AYsqAUAimeiOmfPECkOXtCWqYtuKrqVX6k26DOppC74qbJEl_8Iojm-yn= PIyiCfeNtY13adK3mY0lnso$ for graphic product...

ATTN...WFO...BMX...CAE...CHS...FFC...JAX...MOB...TAE...

ATTN...RFC...SERFC...NWC...

LAT...LON 33618302 33498228 33078167 32528146 31768171=20
30898320 30198408 29568500 30128734 31088690=20
32538513 33028448 33508380=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 040556
FFGMPD
NVZ000-CAZ000-041800-

Mesoscale Precipitation Discussion 0018
NWS Weather Prediction Center College Park MD
1256 AM EST Tue Feb 04 2025

Areas affected...Central and Northern California

Concerning...Heavy rainfall

Valid 040600Z - 041800Z

SUMMARY...Heavy rain associated with the ongoing atmospheric river
may locally reach rates to 1 inch per hour with any convective
banding and heavier showers through mid-morning.

DISCUSSION...The primary AR has shifted into the Bay Area and
northeast through Sacramento this evening. For most areas, the
rain is generally light to moderate, producing 1/10 to 1/4 inch
per hour rates. The higher 1/4 inch per hour rates are largely on
the windward (southwest-facing) sides of the coastal ranges and
the Sierras. Onshore flow to 40 kt at 850 continues into the Bay
area. Upon moving inland the flow shifts to southerly as it tracks
along the foothills of the Sierras up the Sacramento Valley. This
low level jet has been the primary driver of the moisture
advection producing locally heavier rains in the form of
convergent bands and enhanced upslope rainfall activity over the
past few days. Since the LLJ isn't going anywhere, these local
"flare-ups" of heavier rain will continue through the overnight
and into Tuesday morning.

The band is expected to shift south of the I-80 corridor by around
10Z/2am PST based on all of the latest HiRes guidance. This will
leave the I-80 corridor from San Francisco through Sacramento in
off-and-on shower activity. The band will taper a bit as it stalls
out generally from a Monterey to Modesto line through the rest of
the overnight and into Tuesday morning. For far northern
California, the area is in a much needed break right now in most
areas, though very light rain and higher elevation snow continues
north of Redding. This break in the rain will continue through at
least sunrise as noted by the relative lack of higher cloud cover
off the coast of California on the graphic.

The next low is following swiftly behind this latest round.
Guidance has shifted significantly northward in the latest runs.
Thus, now expect another round of heavy rain to impact much of the
Sacramento Valley, including the hard-hit Redding area. This
heavier rain will arrive with the next low around 15Z/7am PST. IVT
values with the low will increase to around 750 kg/ms according to
CW3E interpolations of the GFS along the coast. The low will be
supported by a quickly-advancing zonal jet stream moving in from
the Pacific, so northern California will be in the left exit
region of that jet. The surface low will thus be supported by
favorable upper level dynamics. The heavy rain will be further
supported by the strengthening LLJ in the Sacramento Valley, which
will intensify in response to the approaching low and increasing
pressure gradient. It's likely that any 1 inch per hour rates with
any convergent bands will occur from mid-morning on due to the
additional moisture and advection.

Any resultant flooding from the heavy rain will likely be confined
to urban areas and flood-prone streams and creeks.

Wegman

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!59G7LOfcoquUdQ5I44TLMUtD7kBqieQZlczqOHpWckco43BIlk7w5Dc1x577hsedxg-G= epVnUC0EIUZOlvbjghhm55A$ for graphic product...

ATTN...WFO...EKA...HNX...MFR...MTR...REV...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 41642113 41392063 40972019 40202000 39102000=20
38591974 38091969 37492045 37112124 36902191=20
36992236 37492259 37812264 37972309 38182304=20
38992387 39512390 39902398 39952396 40322377=20
40672325 41062280 41582213=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 120928
FFGMPD
MSZ000-LAZ000-ARZ000-TXZ000-121526-

Mesoscale Precipitation Discussion 0029
NWS Weather Prediction Center College Park MD
427 AM EST Wed Feb 12 2025

Areas affected...much of Louisiana, central/southern Mississippi,
and a small part of east Texas

Concerning...Heavy rainfall...Flash flooding possible

Valid 120926Z - 121526Z

Summary...Convective bands will continue to increase and grow
upscale into clusters and lines while moving eastward across the
discussion area. A few areas of 1-2 inch/hr rain rates are
expected, which should pose a flash flood risk especially near
sensitive areas.

Discussion...Over the past hour or so, radar mosaic imagery has
depicted a distinct uptick in convective activity across east
Texas and Louisiana. The increase in convection is likely tied to
a dramatic increase in southerly 850mb flow along the Sabine River
Valley (into the 40-60 kt range) along with attendant
convergence/ascent. The eastward movement of a distinct mid-level
shortwave trough and steep lapse rates aloft were also
contributing factors to the increase in convection. Most storms
are elevated above a cool stable boundary layer, although mergers
and growth into linear segments with localized training have
already been observed near/just east of Lufkin, where spots of 1
inch/hr rain rates were already estimated via MRMS.

These convective trends are expected to continue, with
observations and CAMs both suggestive of upscale growth into one
or two dominant complexes that move eastward across the region.=20
Many cell mergers are anticipated and localized training will
remain a distinct possibility. These factors should contribute to
occasional 1-2 inch/hr rain rates at times as storms move eastward
through the discussion area. These rates should approach FFG
thresholds - especially along an axis from Lufkin to Greenville to
Columbus where prior rainfall has contributed to wet soils and
<1.5 inch/hr FFG thresholds. Prolonged rainfall along and south
of this axis (i.e., greater than 1 hour of heavy rainfall) may
also result in flash flooding. This threat is expected to persist
through 15Z, with occasional convective redevelopment in east
Texas indicated in the models throughout the morning.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7lIa7zzacsrpPgW07lPFC80pQTiBIi1dUIuuMNf9dXQ_UvaMihtl4fGGQ3H3scWSq11f= CVF68sukC-fDK3-OoZLRXG4$ for graphic product...

ATTN...WFO...HGX...JAN...LCH...LIX...MEG...SHV...

ATTN...RFC...LMRFC...SERFC...WGRFC...NWC...

LAT...LON 33888837 33218839 32128857 31239008 30539215=20
30489469 31609498 32489388 33409101 33838960=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 121519
FFGMPD
MSZ000-LAZ000-ARZ000-TXZ000-122031-

Mesoscale Precipitation Discussion 0030
NWS Weather Prediction Center College Park MD
1018 AM EST Wed Feb 12 2025

Areas affected...Lower Missisippi Valley

Concerning...Heavy rainfall...Flash flooding possible

Valid 121518Z - 122031Z

Summary...Showers and thunderstorms will expand in coverage and
begin to train from SW to NE through the afternoon. Rainfall rates
in excess of 1"/hr will become more common, which through training
may produce 2-3" of rain. This could lead to instances of flash
flooding.

Discussion...The regional radar mosaic this morning depicts two
areas of heavy precipitation spreading across portions of the Gulf
Coast and lower Mississippi Valley states. A meandering stationary
front analyzed by WPC draped from northern MS into eastern TX is
providing focus for a corridor of convection, while a more broad
warm front slowly lifting across LA/MS is helping to spawn warm
advection showers and isolated thunderstorms. In general, rainfall
rates this morning have been between 0.25 and 0.5 inches per hour,
but a few embedded 1"/hr cells have recently been observed via
MRMS radar estimates. This has produced locally 2-3" of rain in
the past 6 hours, and a few flood advisories are currently in
effect.

As the morning progresses into the afternoon, upstream troughing
across the Central Plains will amplify, with synoptic ascent
becoming enhanced across the region through height falls, PVA, and
an intensifying jet streak aloft. Together, this will help lift
the warm front more steadily northward, leading to greater
instability drawing northward and impinging into the stationary
front. This is reflected by impressive moisture transport vector
convergence later this morning, especially from northern LA into
northern MS. As CAPE climbs to 500-1000 J/kg, this will support
more widespread convective rain rates which the HREF indicates
have a 20-40% chance of exceeding 1"/hr, with short term rain
rates potentially eclipsing 2"/hr as shown by the HRRR 15-min
fields. Storm motions will remain quick on 850-300mb winds of
40-60 kts, but organization along this boundary and some
backbuilding into TX will support training. This suggests that
despite the fast motion of individual cells, some areas may pick
up 2-3" of rain.

The soils across this region are generally saturated as noted via
NASA SPoRT 40cm soil moisture that is around the 90th-95th
percentile. This has reduced FFG to just 1-2"/3 hrs, or less, in
many areas, for which the HREF suggests has a 20-50% chance of
exceedance in the next few hours. This is further reflective of
the isolated potential for flash flooding into this afternoon.


Weiss

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5eDLGJEwOksezvhbZNpBWprRz3gZUBB61rszsHvK2Q2fLtc_mwlEocph5LRwhyUAkwSs= tbV3sRDDzZmp40aMZ8EYLHo$ for graphic product...

ATTN...WFO...JAN...LCH...LZK...MEG...SHV...

ATTN...RFC...LMRFC...SERFC...WGRFC...NWC...

LAT...LON 34238926 33958850 33368831 33048848 32578930=20
32039023 31339199 31039338 31069381 31169418=20
31549474 32279439 32789356 33479207 33969096=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 122026
FFGMPD
ALZ000-MSZ000-LAZ000-130215-

Mesoscale Precipitation Discussion 0031
NWS Weather Prediction Center College Park MD
326 PM EST Wed Feb 12 2025

Areas affected...Lower Mississippi Valley through Northern Alabama

Concerning...Heavy rainfall...Flash flooding possible

Valid 122024Z - 130215Z

Summary...Showers and thunderstorms rapidly blossoming within a
warm sector will expand in coverage and intensify through the
afternoon. These thunderstorms will lift northward and then train
SW to NE ahead of a cold front, with rainfall rates as much as
2-3"/hr. This could lead to instances of flash flooding.

Discussion...The regional radar mosaic across the Gulf Coast this
afternoon depicts rapidly expanding and intensifying thunderstorms
along and just south of a warm front from LA to the FL Panhandle.
This convection is expanding within a pronounced warm sector
characterized by favorable instability (MLCAPE 1000-2000 J/kg) and
elevated PWs (1.6 to 1.8 inches) according to the SPC
mesoanalysis. Additionally, recent VWPs from the region indicate
modest low-level veering but with strong inflow, supporting large
updrafts capable of producing intense rainfall rates. This is
being analyzed by recent MRMS 15-min rainfall as high as 0.75"
(3"/hr rates), resulting in rising CREST unit streamflow values
across parts of LA and MS. Upstream of this fresh convection, a
wave of low pressure and attendant cold front are analyzed by WPC
crossing from TX into LA, along which additional thunderstorms are
occurring with current FFWs.

As the afternoon progresses into the evening, the environment
should become increasingly unstable as the plume of 1000-2000 J/kg
MLCAPE surges as far north as Birmingham, concurrent with elevated
PWs being drawn northward. This plume of robust thermodynamics
will be advected on 850mb inflow that is progged to reach 50+ kts,
resulting in 850-700mb moisture flux that may exceed 5 sigma
according to the SREF. Additionally, increasing synoptic lift
within the RRQ of an intensifying jet streak will support an
expansion of convection into the evening, with thunderstorms
likely aligning along or just ahead of the convergence axis of the
approaching cold front as it squeezes the warm sector. This
alignment will rapidly enhance the flash flood risk, as training
of cells along the boundary will offset the limiting storm speed
of 40-60kts.

The HREF suggests that coverage of rainfall rates exceeding 1"/hr
will expand, and the HRRR 15-min progs suggest rainfall intensity
may produce 0.75 to 1 inch of rain in as little as 15 minutes.
These rates themselves could cause instances of flash flooding,
but where training occurs, more than 3" of rain is possible,
enhancing the flash flood risk. The most likely locations for any
flash flooding will be across urban areas as soil moisture in
southern LA, MS, AL is drier than normal according to NASA SPoRT.
However, training of these intense rain rates could quickly
overwhelm even the drier soils, so flash flood instances are
possible anywhere across the discussion area into this evening.


Weiss

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7HS20P0xpH_2YeArlrAwCpCkIcjONWRgMCzQPbWsAxBFJQAM3nSAqEdYjgbLbHzZEWoP= UGLjng9UesXPUWDHdCY15PE$ for graphic product...

ATTN...WFO...BMX...HUN...JAN...LCH...LIX...MEG...MOB...SHV...

ATTN...RFC...LMRFC...SERFC...NWC...

LAT...LON 34828712 34538627 33658599 32878613 32308688=20
31708793 31268939 30989077 30979206 30969237=20
31009261 31569255 32349167 34568837=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 150722
FFGMPD
TNZ000-KYZ000-ILZ000-MOZ000-ARZ000-151315-

Mesoscale Precipitation Discussion 0037
NWS Weather Prediction Center College Park MD
220 AM EST Sat Feb 15 2025

Areas affected...northeastern AR across MS Valley into KY and TN

Concerning...Heavy rainfall...Flash flooding possible

Valid 150717Z - 151315Z

SUMMARY...The threat for flash flooding will steadily increase
over the next 3-6 hours from northeastern AR, across the MS Valley
and into KY and TN. Training and repeating rounds of rain will
produce peak hourly rainfall of 0.5 to 1.5 inches and 6 hour
totals of 1 to 2 inches, locally as high as 3 inches.

DISCUSSION...Scattered showers and elevated thunderstorms were
observed to be increasing in coverage over portions of the lower
and middle MS Valleys in association with strong low level warm
air advection. 850 mb winds were from the S to SW, peaking around
70 kt in southern MO (per VAD wind data). Layered PW imagery
showed the rapid northward return of moisture from the eastern
half of TX into the lower MS Valley (surface to 700 mb layers),
allowing for the swift development of MUCAPE from west to east as
dewpoints in the lower layers of the troposphere increase,
allowing parcels to make use of relatively steep 700-500 mb lapse
rates (6-7 C/km).

Regional radar imagery at 07Z showed a persistent region of
elevated convection from northeastern AR into northwestern TN,
co-located with an axis of moisture flux convergence located at
the leading edge of low level moisture return. Alignment of this
axis and the mean steering flow from the WSW has caused training
and repeating rounds of heavy rain to affect portions of
northeastern AR into far northwestern TN. Local Wunderground
rainfall network observations have shown 0.3 to 0.6 inches of rain
within 30 minutes and one report as high as 0.7 inches in 30
minutes, just south of the MO Bootheel from ~06Z.

Expectations are for continued low level warm air advection to
maintain the trend of increasing MUCAPE values toward the east,
supporting elevated thunderstorms into central KY/TN later this
morning. RAP forecasts indicate little latitudinal movement of the
elevated zone of low level convergence over the next several hours
and additional upstream development is anticipated over AR in the
12-15Z window as forcing for ascent increases ahead of an
approaching shortwave trough axis which extended from the central
High Plains into the Desert Southwest at 07Z. Repeating rounds of
showers and thunderstorms will continue through the morning with
periodic episodes of training which will translate into locally
high rainfall rates.

Soil moisture across a large portion of the region is above
average due to recent rainfall and/or snow melt. As a result, FFG
values are low, with less than 2 inches in 3 hours along the KY/TN
border and less than 2.5 inches in 3 hours closer to the MS River.
While this MPD is tagged with flash flooding "possible", the
threat is only expected to increase over the region during the
daytime hours.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_LKzuenuFE5n5GFxs7T9W29CMESBylqN1j8oHhWN0qhcWfw7cdPyRqwFnLJlnpYxzdkU= PZuwZc4Uo9CGdNvPzJ_r8YM$ for graphic product...

ATTN...WFO...JKL...LMK...LZK...MEG...MRX...OHX...PAH...SGF...

ATTN...RFC...ABRFC...LMRFC...OHRFC...NWC...

LAT...LON 37398765 37278539 36858434 36188435 35808534=20
35518752 35158996 34769206 35459269 36329152=20
37068991=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 151332
FFGMPD
VAZ000-WVZ000-TNZ000-KYZ000-INZ000-MSZ000-MOZ000-ARZ000-151930-

Mesoscale Precipitation Discussion 0038
NWS Weather Prediction Center College Park MD
830 AM EST Sat Feb 15 2025

Areas affected...Portions of the OH/TN Valleys and Mid-South

Concerning...Heavy rainfall...Flash flooding likely

Valid 151330Z - 151930Z

SUMMARY...An expansive axis of heavy showers and thunderstorms
with strong cell-training concerns will be promoting a widespread
flash flood threat over the next several hours across portions of
the OH/TN Valley region and Mid-South.

DISCUSSION...The latest GOES-E IR satellite imagery shows an
expansive areas of heavy shower and thunderstorm activity
impacting areas of eastern AR up across central and western TN and
much of central and southern KY. Light to moderate stratiform
rains are noted north of here closer to the OH River and also into
the central Appalachians.

The convection that is organizing is associated with strong warm
air advection which is being aided by a powerful southwest
low-level jet of 50 to 60+ kts overrunning a strong frontal zone.
This is driving very strong moisture transport which is showing up
in an impressive fashion with the experimental CIRA-LVT (Layered
Vapor Transport) imagery as it is depicting SFC/850 layer LVT
magnitudes of 300+ kg/m/s. Meanwhile, a nose of MUCAPE values on
the order of 500 to 1000 J/kg is now oriented up across central to
northeast AR through western TN and western KY and this is helping
to facilitate the broader axis of elevated convection.

Over the next several hours, very strong warm air advection and
moisture transport will continue to support organizing bands of
convection that will be aligned with the deeper layer mean flow
and thus will be conducive for a substantial level of
cell-training. Increasing CAPE values with time along with
strengthening shear profiles will support stronger convective
elements that will yield increasingly heavy rainfall rates.

Rainfall rates with the stronger storms may reach as high as 1 to
1.5 inches/hour at least going through midday, but with
significant cell-training concerns, this may result in some
rainfall amounts by early afternoon alone of 2 to 4 inches. The
latest CAM guidance suggests areas of western/northern TN through
southern KY will have the heaviest totals going through the 18Z to
20Z time frame, with somewhat lesser amounts farther north.

Given the extremely sensitive/saturated soil conditions and
already elevated streamflows for many locations, these rainfall
totals over the next several hours are likely to begin resulting
in widespread flash flooding. Additional MPDs will be issued this
afternoon to update what should evolve into a high-impact and
life-threatening flash flood event in time.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9YBX9aJ4KgA8Z4iKzzTmNqcBfe8AW-uZDjSAoMlL6IbG7HtnQ7qDKHisENvc779BvUjO= SUH7voR82zaHIzanXz9Ys10$ for graphic product...

ATTN...WFO...JKL...LMK...LZK...MEG...MRX...OHX...PAH...RLX...

ATTN...RFC...LMRFC...OHRFC...NWC...

LAT...LON 38438386 37938214 36958191 36258289 35938480=20
35578763 34359122 34619187 35219176 36318988=20
37208813 38008597=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 151701
FFGMPD
VAZ000-WVZ000-152300-

Mesoscale Precipitation Discussion 0039
NWS Weather Prediction Center College Park MD
1200 PM EST Sat Feb 15 2025

Areas affected...Central Appalachians and Portions of the VA
Piedmont

Concerning...Heavy rainfall...Flash flooding possible

Valid 151700Z - 152300Z

SUMMARY...Heavy rainfall moving into the central Appalachians and
adjacent areas of the VA Piedmont coupled with areas of melting
snow will set the stage for areal flooding and possible flash
flooding going through the afternoon hours.

DISCUSSION...The latest radar imagery shows moderate to heavy
rainfall along with locally some mixed precipitation that is in
the process of changing to rain advancing east across the central
Appalachians with southern WV and southwest VA seeing generally
the heaviest corridor of higher rainfall rates. The rainfall is
associated with strong warm air advection and moisture transport
into the region which is being aided by a southwest low-level jet
of 40 to 50 kts.

Instability is generally non-existent, but the level of isentropic
ascent and low-level frontogenetical forcing is quite strong and
is supporting rainfall rates of a 0.25" to 0.50"/hour. Meanwhile,
heavier rains are noted locally upstream over areas of central and
eastern KY which will be advancing eastward this afternoon, and
with an additional strengthening of the low-level jet expected
this afternoon, somewhat heavier rates that may exceed a
0.50"/hour will be possible over areas of southern WV down through
southwest VA. Some very modest intrusion of elevated instability
may arrive toward this evening that may also support a few
thunderstorms capable of producing these heavier rates.

The 12Z HREF guidance suggests additional rainfall amounts of as
much as 1 to 2+ inches by early this evening. These rains coupled
with warmer temperatures and a melting snowpack over some of the
higher terrain, and already high streamflows, will favor an
increasing concern for areal flooding and potentially some flash
flooding where these heavier rainfall rates can focus and persist.
Conditions will continue to be closely monitored over the next
several hours.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9CXcnsAJgEF_8dcauc9YTCzQK2Ukg73QSPRiGtp6YqQvqygLqPd4dqwi8v6lfNypQH5a= JsyKzLS8e6_RN0Yz9pC3E8A$ for graphic product...

ATTN...WFO...LWX...MRX...RLX...RNK...

ATTN...RFC...LMRFC...MARFC...OHRFC...SERFC...NWC...

LAT...LON 38808007 38567930 38127898 37597888 37007910=20
36707971 36598126 36708187 37698188 38258235=20
38578216 38798126=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 151856
FFGMPD
TNZ000-KYZ000-ILZ000-MSZ000-MOZ000-ARZ000-160055-

Mesoscale Precipitation Discussion 0040
NWS Weather Prediction Center College Park MD
155 PM EST Sat Feb 15 2025

Areas affected...Lower MS Valley into the Mid-South and OH Valley

Concerning...Heavy rainfall...Flash flooding likely

Valid 151855Z - 160055Z

SUMMARY...Flash flooding will become more expansive and
significant going into the early evening hours as heavy showers
and thunderstorms organize and train over the same area. Some of
the flash flooding is expected to be extremely dangerous and
life-threatening.

DISCUSSION...Strong shortwave energy ejecting east out across the
southern Plains will be encroaching on the Lower MS Valley this
afternoon and will be interacting with a moist and increasingly
unstable airmass which coupled with strengthening shear profiles
will set the stage for expanding clusters of strong to severe
thunderstorms. This is likely to include a combination of
multicell and supercell convection which will be embedded within
an environment conducive for yielding very heavy rainfall rates.

GOES-E visible satellite imagery shows a notable increase in cloud
street activity across LA/MS and through central and southern AR
which is indicative of an increasingly unstable boundary layer.
Diurnal heating via solar insolation has allowed for MLCAPE values
to increase to 1000 to 1500 J/kg, and these values will continue
to increase over the next few hours. A quasi-stationary front is
draped from the Arklatex northeastward into northern MS and far
southwest TN with multiple waves of low pressure noted along it.
Meanwhile, a powerful southwest low-level jet is in place reaching
upwards of 50 to 60+ kts and this is yielding very strong moisture
transport from the Gulf of America up across the broader Lower MS
Valley and Mid-South region with PWs that have now increased to
1.3 to 1.5 inches.

As thunderstorms continue to develop and organize over the next
several hours, there will be rainfall rates capable of reaching
1.5 to 2 inches/hour with the stronger cells. Cell-merger and
cell-training concerns will increase by later this afternoon and
this evening with potentially some QLCS-related training of storms
possible in the 21Z to 00Z time frame from south-central to
northeast AR into the MO Bootheel, northwest TN and far southwest
KY. This is favored by a consensus of the 12Z HREF and the 16Z to
18Z runs of the experimental WoFS guidance which shows a
combination of multicell, supercell and QLCS-driven convection
heading into the evening hours.

Additional rainfall amounts of as much as 3 to 6 inches are
expected within the corridors of greatest cell-training which
currently is being most favored across northeast AR into the MO
Bootheel, northwest TN and far southwest KY going through 00Z.
Given that some of these areas already have flash flooding
ongoing, the additional rains are likely to foster extremely
dangerous and life-threatening flash flooding conditions by this
evening, with Flash Flood Emergency level impacts possible. As
conditions evolve this evening, additional MPDs will be issued to
address this high-impact event.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5sDaEqb8kaaqOtjNqI9qjq4Zfoa4R4X76DNCTY7jrCBOcSZPwnFV4Z8bjoJSYUeH8OqW= QlIa7Da_Ddzeh7AkvK07zns$ for graphic product...

ATTN...WFO...LMK...LZK...MEG...OHX...PAH...SGF...SHV...

ATTN...RFC...ABRFC...LMRFC...OHRFC...NWC...

LAT...LON 37798645 37448527 36658564 36088783 34629061=20
33119252 33099332 33889348 35589251 36809080=20
37528852=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 151947
FFGMPD
VAZ000-WVZ000-OHZ000-TNZ000-KYZ000-INZ000-160145-

Mesoscale Precipitation Discussion 0041
NWS Weather Prediction Center College Park MD
246 PM EST Sat Feb 15 2025

Areas affected...Portions of the OH/TN Valleys and Central
Appalachians

Concerning...Heavy rainfall...Flash flooding likely

Valid 151945Z - 160145Z

SUMMARY...Locally significant flash flooding is expected going
into the evening hours from persistent heavy rainfall over
saturated soils.

DISCUSSION...The latest GOES-E IR satellite imagery along with
dual-pol radar shows an expansive area of heavy rain continuing to
advance west to east across central and eastern KY and into
southwest VA and southern WV. The activity continues to be
associated with strong warm air advection which is being aided by
a powerful southwest low-level jet of 40 to 60+ kts overrunning a
strong frontal zone.

This is driving very strong moisture transport with magnitudes in
the SFC/850 mb layer of as much as 320 kg/m/s aiming across much
of western and central TN and toward southern KY as seen in the
experimental CIRA-LVT (Layered Vapor Transport) imagery. Some very
modest instability with MUCAPE values of as much as 100 to 250
J/kg is noted over the region and this has been supporting some
occasional elevated convective elements.

Over the next several hours heading into the evening, there will
continue to be a west to east axis of heavy rainfall given the
level of strong isentropic ascent and frontogenetical forcing, but
as a warm front lifts north with time, this band of heavy rainfall
should also gain latitude with the rain eventually getting into
more of north-central to northeast KY and central WV.

The rainfall rates should be able to at least occasionally reach
into the 0.50" to 0.75"/hour range, and especially with any
stronger convective elements that continue to materialize. These
rates and overall persistence of heavy rainfall should support
additional rainfall totals by early this evening of 1 to 2 inches
with locally higher amounts.

Many areas have ongoing areal flooding and flash flooding, and
with extremely sensitive/saturated soil conditions and very high
streamflows, much of the additional rainfall will lead to
immediate runoff and potentially support significant flash
flooding for some locations. This will include areas of the
central Appalachians for locations that currently also have a
melting snowpack and thus added water runoff concerns.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_x0dK2JV4HgGIM65ux75coVlDb0zP0EKlMSOCYp6OUxNID4h2UFh_3Lze1FX9vfrroeP= NMzW9UPAY6yLbhgB4ivmMHs$ for graphic product...

ATTN...WFO...ILN...JKL...LMK...LWX...MRX...OHX...RLX...RNK...

ATTN...RFC...LMRFC...MARFC...OHRFC...SERFC...NWC...

LAT...LON 38868096 38507991 38007962 37197993 36698093=20
36348411 36568591 37358642 37988611 38578432=20
38848255=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 160046
FFGMPD
OHZ000-TNZ000-KYZ000-INZ000-ILZ000-MSZ000-MOZ000-ARZ000-160645-

Mesoscale Precipitation Discussion 0042
NWS Weather Prediction Center College Park MD
745 PM EST Sat Feb 15 2025

Areas affected...Lower MS Valley into the Mid-South and OH Valley

Concerning...Heavy rainfall...Flash flooding likely

Valid 160045Z - 160645Z

SUMMARY...Widespread flash flooding with damaging and
life-threatening impacts will continue as showers and
thunderstorms continue to train locally over the same area and
focus heavy rainfall totals.

DISCUSSION...The latest GOES-E IR satellite imagery along with
dual-pol radar shows widespread and well-organized showers and
thunderstorms impacting much of the Lower MS Valley with a
northeastward extension up across portions of the Mid-South and
the OH Valley. Strong shortwave energy is crossing the Arklatex
and will be rapidly lifting northeastward into the OH Valley
overnight. As it does so, the energy will be interacting with a
moist and moderately buoyant airmass continuing to surge
northeastward from the Lower MS Valley.

This airmass is characterized by MUCAPE values of as much as 1000
to 1500 J/kg and PWs approaching 1.5 inches which is also being
aided by the persistence of a powerful 50 to 60+ kt southwest
low-level jet. Radar imagery shows a QLCS currently evolving from
eastern AR up across western TN and western KY with some embedded
supercell convection. The better thermodynamics are situated from
southeast AR through northern MS and into western TN and this
should provide convective sustenance through the remainder of the
evening hours as the overall QLCS activity advances off to the
east.

While the southern flank of the overall convective footprint this
evening should become increasingly progressive as a cold front
arrives from the west, there will still be notable concerns for
training showers and thunderstorms for several more hours farther
off to the northeast in close vicinity of a warm front lifting
north through the OH Valley.

Rainfall rates with the stronger storms over the next several
hours will still be capable of reaching 1.5 to 2 inches/hour with
the strongest of cells. Additional rainfall amounts going through
06Z may reach as high as 2 to 4 inches with isolated heavier
amounts not out of the question.

Many areas have already received 2 to 4 inches of rain since early
this morning, and the extremely sensitive ground conditions with
saturated soils and ongoing widespread areas of flash flooding
coupled with the additional rainfall, will pose concerns for
potentially Flash Flood Emergency level impacts with damaging and life-threatening conditions. This situation will continue to be
closely monitored.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-u7CK8MFFfh285T7L6vQEdWwmFqgQ4JozDgaBI4lhPBu2Yio0WTPIyifjGyhjkKWHNON= Qc75AzU5U893xOknW4FalYw$ for graphic product...

ATTN...WFO...ILN...JKL...LMK...LZK...MEG...MRX...OHX...PAH...
RLX...

ATTN...RFC...LMRFC...OHRFC...NWC...

LAT...LON 38918407 38398319 37498313 36788408 36358516=20
35508719 34558970 34249121 34669174 35549119=20
36728984 37428858 38068736 38868545=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 160121
FFGMPD
TNZ000-ALZ000-MSZ000-LAZ000-ARZ000-160720-

Mesoscale Precipitation Discussion 0043
NWS Weather Prediction Center College Park MD
820 PM EST Sat Feb 15 2025

Areas affected...Northern LA...Central and Northern MS...Western
and Northern AL...Middle TN

Concerning...Heavy rainfall...Flash flooding possible

Valid 160120Z - 160720Z

SUMMARY...Heavy showers and thunderstorms will be sweeping across
the region over the next several hours which may produce some
areas of flash flooding, with especially the more urbanized
locations at risk for potential runoff problems.

DISCUSSION...Radar and satellite imagery shows an evolving QLCS
crossing through areas of eastern AR through western TN, with more
broken clusters of organized convection including a few supercells
down across areas of northern LA which is beginning to move into
areas of western MS.

The airmass downstream of the current convection is moist and
moderately buoyant with MLCAPE values of 1000 to 1500 J/kg locally
and PWs of near 1.5 inches. However, a substantial amount of shear
remains in place ahead of the strong shortwave and attendant
frontal system crossing the Lower MS Valley. A very strong
low-level jet of 50 to 60+ kts remains a key player in driving
enhanced moisture/instability transport and this will sustain the
convective threat well into the overnight hours as a cold front
approaches and eventually crosses the region.

Rainfall rates associated with the QLCS and more discrete
supercell activity over the next several hours will likely reach
as high as 1.5 to 2 inches/hour, and there may be at least some
occasional cell-merger and cell-training activity that will
support some locally excessive rainfall totals that may reach 2 to
4 inches.

NASA SPoRT data shows antecedent soil conditions on the moist side
across much of the region given the heavy rainfall that occurred a
few days ago. This coupled with the locally heavy convective rains
over the next several hours may pose at least some concern for
areas of flash flooding. However, generally the more urbanized
locations will be at greatest risk for runoff problems and impacts
heading into the overnight hours.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_dh-UctBjAzaR5XuVslTA7kCWT2U17Uy4b4tnD0KR7Ikw5OL3TSB6yB3TtpYwMlaiFlY= TmhjBMfPKLhR7eOGB3-TFn0$ for graphic product...

ATTN...WFO...BMX...HUN...JAN...LCH...LIX...LZK...MEG...MRX...
OHX...SHV...

ATTN...RFC...LMRFC...OHRFC...SERFC...NWC...

LAT...LON 36018588 35688528 34408623 32918779 31708932=20
31109076 31149210 31389265 31909290 32679249=20
33559157 34289031 35008825=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 160202
FFGMPD
PAZ000-MDZ000-VAZ000-WVZ000-OHZ000-KYZ000-160800-

Mesoscale Precipitation Discussion 0044
NWS Weather Prediction Center College Park MD
901 PM EST Sat Feb 15 2025

Areas affected...Portions of the OH Valley and Central
Appalachians

Concerning...Heavy rainfall...Flash flooding likely

Valid 160200Z - 160800Z

SUMMARY...Locally significant and life-threatening flash flooding
will continue into the overnight hours with additional Flash Flood
Emergency level impacts possible from additional rounds of heavy
rainfall, with the central Appalachians continuing to see the
greatest risk of this.

DISCUSSION...The latest radar imagery continues to show an
expansive area of heavy rainfall impacting areas of mainly
north-central to northeast KY through central WV and down into
areas of south-central VA. The activity continues to be associated
with strong warm air advection which is being aided by a powerful
southwest low-level jet of 40 to 60+ kts surging up through the
OH/TN Valley region and into the central Appalachians.

Very strong transport continues as a result which coupled with
enhanced isentropic ascent and frontogenetical forcing continue to
yield heavy rainfall rates generally in the 0.25" to 0.50"/hour
range with some occasionally heavier rates where some embedded
elevated convective elements focus. Some very modest instability
with MUCAPE values of as much as 100 to 250 J/kg is noted over the
region and this continues to favor at least some transient pockets
of convection.

A warm front continues to gradually lift north into the OH Valley
and central Appalachians and this is allowing for the overall
heavy rainfall shield to gain latitude. Going into the overnight
hours, rainfall rates should still be capable of reaching a
0.50+"/hour locally and especially with the aforementioned pockets
of elevated convection. Additional rains of as much as 1 to 2
inches will be possible over the next 6 hours, with areas closer
to the OH River involving northeast KY and southern OH seeing
potentially 2 to 3 inches given heavier rainfall approaching from
western KY including some stronger pockets of even stronger
convection.

Given the additional rainfall and ongoing widespread focus of
areal flooding and flash flooding, significant and
life-threatening flash flooding is likely to continue with
additional potential for Flash Flood Emergency level impacts. This
will especially be the case over portions of the central
Appalachians where there have already been a total of 4 Flash
Flood Emergencies issued since early this afternoon.
Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8Fg8Ag0Kz6_p6CldtRGTmShLNnTzxgtRFgJQKMCYiQiuItEFTm3kwmTWjaghChzH9c0f= cMRalbMI6zKUo33LWwfq1OI$ for graphic product...

ATTN...WFO...ILN...JKL...LMK...LWX...PBZ...RLX...RNK...

ATTN...RFC...MARFC...OHRFC...NWC...

LAT...LON 39878106 39677973 39037917 38167920 37658001=20
37598196 37648310 37888390 38408422 39038417=20
39528328 39768232=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 160432
FFGMPD
PAZ000-WVZ000-OHZ000-KYZ000-INZ000-161000-

Mesoscale Precipitation Discussion 0045
NWS Weather Prediction Center College Park MD
1132 PM EST Sat Feb 15 2025

Areas affected...southwestern to eastern OH into western PA

Concerning...Heavy rainfall...Flash flooding possible

Valid 160430Z - 161000Z

SUMMARY...Localized flash flooding will be possible from portions
of southwestern OH into eastern OH and western PA through 10Z.
Peak rainfall rates between 0.50 and 0.75 in/hr may occur but most
locations should see lower rates. Still, the addition of 1-2
inches of rain over a relatively short period of time atop
sensitive ground conditions may result in localized flash flooding.

DISCUSSION...Regional radar imagery at 04Z depicted an area of
higher reflectivity moving east-northeastward into
southwestern/central OH, just north of MPDs #42 and #44. While
bright banding accounts for these higher reflectivity values with
surface temperatures only in the 30s and 40s, ground observations
have reported peak rainfall rates of about 0.25 to 0.50 inches
(locally higher) to the west and north of Cincinnati within the
last hour. This axis of precipitation is related to a
strengthening zone of low level frontogenesis (850-700 mb),
located north of an approaching surface low in KY, connected to a quasi-stationary front that extended through eastern KY into
north-central WV. SPC mesoanalysis data from 04Z indicated less
than 100 J/kg MUCAPE to the north of the front into OH. Strong
divergence aloft was also present over the region, given the
position of a 180+ kt upper level jet max located over MI and Lake
Huron, placing OH within its favorable right-entrance region.

Short term RAP forecasts indicate the surface low over KY will
steadily track northeastward over the next several hours, allowing
the front to lift north as a warm front through 09Z. This movement
will cause the strong axis of frontogenesis to also lift north
while weak MUCAPE (up to 150 J/kg or so) moves into southeastern
OH and western PA between 06-09Z. Bands of heavy rain are expected
within the broader precipitation shield with occasional rates as
high as 0.50 to 0.75 in/hr. Additional rainfall of 1 to 2 inches
is expected to occur through 10Z from southwestern OH into eastern
OH and western PA. While this region of the Midwest has escaped
the ongoing significant rains and flooding to the south, soils
remain sensitive with low FFG values of only 1 inch in 3 hours
across the upper OH Valley. Localized flash flooding may result
due to an additional 1-2 inches of rain over a fairly short period
of time.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7BAiGOy8kEX0Z4HBYlIicO-KDRnqegYnHBg7SBqOeCHPk2w6XUgTeWNieeac3ajxg3Uv= trfZBU7hi5iGPucbXayZgAw$ for graphic product...

ATTN...WFO...CLE...CTP...ILN...PBZ...RLX...

ATTN...RFC...MARFC...OHRFC...NWC...

LAT...LON 41607951 41217861 40217943 39797989 39858054=20
39788209 39048425 38888491 39668496 40678319=20
41268145=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 160641
FFGMPD
VAZ000-NCZ000-WVZ000-TNZ000-KYZ000-161230-

Mesoscale Precipitation Discussion 0046
NWS Weather Prediction Center College Park MD
140 AM EST Sun Feb 16 2025

Areas affected...Cumberland Plateau into central Appalachians

Concerning...Heavy rainfall...Flash flooding likely

Valid 160639Z - 161230Z

SUMMARY...Despite an expected weakening trend in rainfall
intensity, additional rainfall over a 2-3 hour window will impact
locations of the central Appalachians hard hit on Saturday. Up to
an inch of rain is expected in some locations with rates of 0.25
to 0.5 in/hr. These rains are expected to exacerbate ongoing
flooding concerns.

DISCUSSION...0630Z radar imagery showed that a squall line
extended SSW from southern TN (between I-65 and I-24) into
northwestern AL. An inflection along the line was noted over
southern TN with an inferred low level vorticity max to its west.
North of the inflection point, the convective line was weaker but
still has had a history of producing hourly rainfall in excess of
1 inch over Middle TN since 04Z. The convective line has begun to
outpace many of the 00Z hires models, most notably over AL, likely
not properly capturing the influence of the mesoscale vorticity
max.

Going forward, instability will be a limiting factor to higher
rainfall rate potential across the "northern" locations of eastern
KY, southern WV and western VA. However, recent hires models may
be slightly downplaying rainfall rate potential from the
Cumberland Plateau into the central Appalachians. Current thinking
is that 0.25 to 0.50 in/hr will be possible from eastern KY into
southern WV and western VA with locally higher rates farther south
over eastern TN where up to a couple hundred J/kg of CAPE may be
present to locally boost rainfall intensity. However, heavy
rainfall duration will be limited by the progressive movement of
the convective line across TN.

Farther north into eastern KY, southern WV and western VA, poorer
organization of the line will be somewhat offset by a longer
duration of rainfall, about 2-3 hours is when a majority of the
expected rainfall will fall. Portions of this region have received
heavy rainfall over the past 24 hours and have ongoing/widespread
significant flooding. Up to an additional inch of rain may fall
across these sensitive locations which will act to exacerbate
existing flooding concerns.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4tfc1TY4BPoPr3mT0SExna_-HdVTbXyjJ7Lx8pDjG2Kd9NnJHBU1PtteAsY_pIjgmpr_= j5g0qjkAmSOkRRfFrLxPxJQ$ for graphic product...

ATTN...WFO...JKL...MRX...OHX...RLX...RNK...

ATTN...RFC...LMRFC...MARFC...OHRFC...SERFC...NWC...

LAT...LON 38398034 38327990 37977999 37388020 36928005=20
36508149 36288219 35728344 35498470 35698554=20
36188547 36918424 37558322 37988274 38278199=20
38368112=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 160733
FFGMPD
PAZ000-WVZ000-OHZ000-KYZ000-INZ000-161030-

Mesoscale Precipitation Discussion 0047
NWS Weather Prediction Center College Park MD
233 AM EST Sun Feb 16 2025

Areas affected...upper OH Valley

Concerning...Heavy rainfall...Flash flooding likely

Valid 160730Z - 161030Z

SUMMARY...Moderate to heavy rain will continue to translate east
through the upper OH Valley in the short term with an additional
inch of rain through 1030Z. Renewed flash flooding is expected.

DISCUSSION...0730Z radar imagery showed a leading linear segment
of heavy rain moving through eastern KY, followed by a stratiform
region of moderate to heavy rain over eastern KY. As a low level
vorticity max advances northeast from Middle TN, an 2-3 hour long
duration of stratiform moderate to heavy rain is expected to
advance into eastern KY, southern OH and eventually portions of
western WV. In addition, preceding the stratiform region will be a
leading line of showers with embedded thunderstorms which have had
a history of 0.25 to 0.50 in an hour but with a 0.25 inch or more
in 15 minutes over eastern KY.

As the entire envelope of rain translates toward the
east/northeast, additional totals up to about an inch are expected
through 1030Z, with a likelihood of renewed flash flooding or a continued/worsening of ongoing flooding concerns occurring from
heavy rain which fell over the past 24 hours.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6BP8PzyRHNEKpvsqNiFF7Yyyibfz9nGkUd5w_1SazcpiI6Buo5H2cC0t0gEgqrf8pdsJ= SNCWbBtxqXXKNUUPknncq0Q$ for graphic product...

ATTN...WFO...ILN...JKL...LMK...PBZ...RLX...

ATTN...RFC...OHRFC...NWC...

LAT...LON 40038127 39908038 39558035 39178062 38228193=20
37628302 36958397 36798457 36938503 37448531=20
38198528 39078473 39758323 39958210=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 222021
FFGMPD
CAZ000-ORZ000-WAZ000-230820-

Mesoscale Precipitation Discussion 0048
NWS Weather Prediction Center College Park MD
320 PM EST Sat Feb 22 2025

Areas affected...Pacific Northwest

Concerning...Heavy rainfall

Valid 222020Z - 230820Z

SUMMARY...Atmospheric river conditions arriving across the Pacific
Northwest will bring heavy rainfall in across the coastal ranges
and into the windward slopes of the Cascades later today and
tonight.

DISCUSSION...A series of offshore shortwave impulses lifting
northeastward toward British Columbia over the next 6 to 12 hours
will be bringing an offshore frontal system toward the coastal
ranges of western WA and western OR along with strong atmospheric
river conditions.

The latest GOES-W WV suite along with CIRA-ALPW and experimental
LVT data shows a very well-defined trans-Pacific fetch of deep
moisture extending from just offshore of the Pacific Northwest
southwestward all the way down to northwest of Hawaii with notable
tropical origins of some of the moisture transport. Multiple
low-amplitude shortwave impulses are embedded within this
atmospheric river channel, and this will help to facilitate strong
warm air advection and onshore flow into especially the coastal
ranges of western WA and western OR along with the windward slopes
of the Cascades by later today and continuing into the overnight
period that will drive locally enhanced rainfall amounts.

PW anomalies are forecast to rise to 2 to 3+ standard deviations
above the climatological mean by 00Z and continue at this level
through tonight as a strong southwest low to mid-level jet sets up
and persists just offshore and overruns the higher terrain of the
Pacific Northwest. In fact, the 850/700mb moisture flux anomalies
are forecast to rise to as much as 3 to 5+ standard deviations
above normal, with one peak this evening by around 00Z and then
another later tonight as the arrival of each shortwave impulse
corresponds to a stronger low to mid-level wind field.

Given the enhanced deep layer warm air advection and moisture
transport along with some of its tropical origin, the rainfall
rates are expected to be efficiently high. The 12Z HREF guidance
shows high probabilities of seeing 0.50" to 0.75"/hour rainfall
rates across the Olympic Peninsula in the 21Z to 00Z time frame,
with portions of the southwest WA coastal range also seeing
elevated probabilities of these rates toward early this evening.
Areas farther east into the windward slopes of the Cascades and
farther south across coastal OR and gradually coastal northwest CA
should see rates easily reach into the 0.25" to 0.50"/hour range
with rates occasionally over a 0.50"/hour.

Over the next 12 hours, some rainfall totals are expected to reach
as high as 3 to 5+ inches over the higher terrain and especially
the favored coastal ranges and upslope areas of the Cascades with
lesser amounts over the adjacent interior valleys/terrain-shadowed
locations. Generally these initial rains are not likely to cause
much in the way of any flooding threat aside from potentially some
localized urban and small stream runoff concerns where the heavier
and more persistent rates set up. However, additional heavy
rainfall beyond this period going into Sunday will gradually raise
the flooding threat.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-Bcn8atyisx4Hf-E9XQot4K2cLaj04bBNcljUCuWosTXrq0j5Uxuq4UDLpO2N8fDN-3m= XFr0k6riV0DfUzAGFmmzU_c$ for graphic product...

ATTN...WFO...EKA...MFR...OTX...PDT...PQR...SEW...

ATTN...RFC...CNRFC...NWRFC...NWC...

LAT...LON 49162120 48902067 48122052 47472075 47002120=20
46402119 45762157 45192153 44712176 44052168=20
43342208 42402211 42282262 42932320 42792371=20
42262360 41472341 40742345 40022393 40282454=20
41532441 43062470 44952423 46622433 47972464=20
48332411 48092348 47562304 47682238 48692234=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 230754
FFGMPD
IDZ000-CAZ000-ORZ000-WAZ000-231800-

Mesoscale Precipitation Discussion 0049
NWS Weather Prediction Center College Park MD
253 AM EST Sun Feb 23 2025

Areas affected...Coastal and Cascade Ranges of S WA, OR & Far
Northwest CA & E WA/SE OR/N ID...

Concerning...Heavy rainfall

Valid 230800Z - 231800Z

SUMMARY...Prolonged AR continues but very broad plume of moisture
will start to focus ahead of next stronger cyclone/frontal push
toward 18z. Deep moisture surges through the Columbia Plateau
into E WA/N ID prepping the soils/increasing run-off ahead of next
surge.

DISCUSSION...GOES-W WV suite shows broad cirrus canopy associated
with polar jet streak and deep atmospheric river extending from
the eastern Pacific across W WA into S British Columbia into the
entrance of the core jet streak that is about 150-160kts. The weakening/initial low level cyclone has occluded northward into
the central BC coastal region with the front extending southward
into/near the Cascade Range, while the warm front extends through
the Columbia River Valley. CIRA LPW, particularly the sfc-850mb
layer bares this evolution out very well with the cold front
starting to sag/stall SW to NE just across the W WA angling back
toward the next approaching stronger wave out near 150W. The
plume remains very broad/wide from the W WA coast to the
Lost/Redwood coast of northwest California with a solid slug of
850-500mb centered on the NW Oregon coast extending back toward
37-38N and 140W; both layers showing associated moisture flux
values running well into 99th percentile for the 20 year record.=20
As such, 1.25" TPW values intersect much of the coastline with
weakly confluent 850-700mb flow angled from the SW about 30
degrees off perpendicular, but given the depth has washed over the
coastal range to to the Cascades. Still, within a broad ascent
pattern in the exiting right entrance pattern provides a
continuation of moderate rainfall rates of .25-.3"/hr, slowly
reducing from north to south across the WA Cascades through the
early morning (but remaining solid further south across OR). This
should result in 2-4" totals across the coastal and Cascade ranges
of Oregon to 18z; with 1.5-2.5" across WA early through 15z.

...Eastern Washington/N Idaho...
As noted above, the broad plume is broad and deep enough to wash
over the coastal range and has begun to fill the Columbia river
Valley into the Plateau region. IVT values of 300-400 kg/m/s will
increase to near 500-600 kg/m/s along 30-45kts of gap flow through
the Plateau into the foothills and eventually higher terrain of SW
WA/NE OR and then toward the Clearwater Range by 12z. Total PWat
values are starting to increase above .75" which would place 90+th
percentile moisture for the date at OTX and GFS/ECMWF flux values
at 3-5 standard anomaly values across the area. While total
moisture is much less than coastal positions, rates of .15-.2" may
occasionally reach .25"/hr with steadily increasing freezing
levels with all but the highest peaks along the ID/MT boarder and
further south across the Blue/Wallowa and Salmon River Ranges
likely to experience more rain than snow/wintry mix. As such
spots of 1-2" totals are expected by 18z. Given the rates are low
and prolonged, this will more likely pre-soak the soils with
slowly increasing run-off values with this particular surge of
moisture...but there is more to come that may be more likely to
result in localized flooding concerns.

...Southwest Oregon/Northwest California...
As the jet streak exits the broader wave of deep moisture will
remained focused across much of OR into NW CA. As the trailing
edge to the prior forcing backs ahead of the next stronger
approaching shortwave/developing low level cyclone/pressure trough
toward 18z, westerly winds will increase into the 45-50kt range
becoming ever so slightly more orthogonal to the boreal rain
forests of SW OR/NW CA. IVT values over 700 kg/m/s combined with
slightly steeper orography will allow for rain-rates to exceed
.5"/hr, occasionally reaching .75"/hr starting around 09-10z.=20
This will be prolonged for about 6-9hrs and potentially result in
localized spots of 4-6". This is not atypical for these
rain-forests but still strong enough for increased run-off and low
end flooding potential before the core of the narrowing AR plume
starts to shift northward with strengthening warm air advection
after 15z.=20

There will remain some timing/uncertainty to the width of the core
of the heavy rainfall surge toward 18z and a subsequent MPD will
be required at that time to provide additional details for the
main surge of heaviest rainfall/highest impacts to this longer
duration AR event.=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7owdNXCQ66se1jmlJbzZ-zMyLYjnzALvV8uQUYrQ9mpQtR3nsZjcZBrTRdwd0abJF_5m= 4ApWn2jy_KJ6iZZehzfp6xA$ for graphic product...

ATTN...WFO...EKA...MFR...MSO...OTX...PDT...PQR...SEW...

ATTN...RFC...CNRFC...NWRFC...NWC...

LAT...LON 48291746 48071637 47651595 46901558 46161514=20
45641539 45411657 45271772 45431937 45052090=20
44302149 42912179 42092223 41482268 40702308=20
40742421 41462419 42772465 43782437 44932423=20
45852415 46742425 47082388 46662330 46602249=20
47772185 47952108 46582112 46142070 46221911=20
47281863 47891828=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 231827
FFGMPD
CAZ000-ORZ000-WAZ000-240625-

Mesoscale Precipitation Discussion 0050
NWS Weather Prediction Center College Park MD
125 PM EST Sun Feb 23 2025

Areas affected...Pacific Northwest

Concerning...Heavy rainfall

Valid 231825Z - 240625Z

SUMMARY...An atmospheric river resurgence this afternoon and
evening will bring a new round of heavy rainfall to the Pacific
Northwest and especially for the coastal ranges and windward
slopes of the Cascades.

DISCUSSION...The latest GOES-W WV suite shows a negatively tilted
upper-level trough in between 40-50N and approaching 130W with an
occluded low center near 48N 142W. This energy will gradually
advance off to the northeast toward the Pacific Northwest and
British Columbia over the next 6 to 12 hours which will bring a
resurgence of stronger atmospheric river conditions back across
the region this afternoon through this evening.

A warm front that is currently oriented west to east across the
Columbia River basin will lift back northward with time as a
strong low to mid-level jet surges northeastward ahead of the
approaching offshore surface low and upper-level trough axis. This
will bring a resurgence of strong warm air advection and moisture
transport into the coastal ranges from far northwest CA up across
western OR and western WA through this evening.

IVT magnitudes are already increasing again across coastal
northwest CA and much of western OR and will be well into the 600
to 800+ kg/m/s range this afternoon through early this evening as
the offshore cold front approaches the region. These IVT values
will increase up across western WA as well, with magnitudes here
generally rising back as high as 400 to 600 kg/m/s.

PW anomalies of 2 to 3+ standard deviations above normal are
forecast through this evening ahead of the cold front and this
coupled with 850/700 mb moisture flux anomalies of 3 to 5+
standard deviations above normal should favor rainfall rates
reaching as high as 0.50" to 0.75"/hour. The heaviest rates should
tend to be focused across the OR coastal ranges and there is some
low-end potential for rates to even approach 1.0"/hour with
arrival of the strongest IVT parameters and forcing later this
afternoon. Enhanced IVT spillover into the windward slopes of the
Cascades should support at least spotty areas of a 0.50" to
0.75"/hour rates here, but the rates overall should tend to be
somewhat more modest farther north into western WA with lower IVT
values and lower PWs by comparison to western OR.

A cold front will advance inland by late this evening and this
will then allow for another break in the overall atmospheric
regime with rates once again then coming back down. However, at
least over the next 6 to 12 hours, expect additional rainfall
amounts of as much as 2 to 4 inches for western OR and 1 to 3
inches for western WA. These rains may bring additional concerns
regionally for runoff problems including small stream and urban
flooding.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!93hHJZr0qetLo277TEuzyb-znKxZjhbG7rVHDOjABuldxUbC_x0FdY6w5DyCIQ6HRfAU= tj3FZEQvAuW0v1Bzdcj-ImY$ for graphic product...

ATTN...WFO...EKA...MFR...OTX...PDT...PQR...SEW...

ATTN...RFC...CNRFC...NWRFC...NWC...

LAT...LON 49162120 48902067 48362056 47722062 47212097=20
46512092 46222066 45892047 45722076 45502126=20
45052150 44542152 43992163 43622194 42852201=20
42442228 42462303 42222342 41652354 41792441=20
43062470 44172437 46192417 47572457 48052414=20
48012332 47762313 47512270 47632198 48432212=20
49032186=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 242025
FFGMPD
ORZ000-WAZ000-250815-

Mesoscale Precipitation Discussion 0051
NWS Weather Prediction Center College Park MD
324 PM EST Mon Feb 24 2025

Areas affected...WA/OR Coastal Ranges into Cascades

Concerning...Heavy rainfall

Valid 242022Z - 250815Z

SUMMARY...Areas of heavy rain will return to the WA and OR Coastal
Ranges and downstream into the Cascades later today/tonight. While
peak rainfall rates may reach/exceed 0.5 in/hr on an isolated
basis, they are much more likely to remain in the 0.2 to 0.4 in/hr
range. 12 hour rainfall of 1-2 inches, locally 3+ inches, is
expected through 08Z.

DISCUSSION...GOES West water vapor imagery at 20Z showed a
well-defined closed low centered just west of 130W near 45N. This
upper low had been strengthening this morning but appears to be
nearing maturity. At the surface, an occluded cyclone was depicted
through visible satellite imagery with the WPC 18Z surface
analysis showing a central pressure of 978 mb and this intensity
is likely close to peak strength. The triple point was located
just near the mouth of the Columbia River and what is left of an
earlier axis of warm advection precipitation was lifting north
through central WA. Meanwhile, radar imagery showed a band of
rain, associated with the approaching cold front, moving just past
the Willamette Valley into the Cascades. The diffluent left exit
region of a mid-upper level jet streak was also located over the
lower Columbia River Valley, likely enhancing lift and enhancing
precipitation intensity.

Short term forecasts from the RAP suggest the closed low will
maintain a similar intensity through about 03Z prior to filling as
it moves toward southern Vancouver Island. The cold frontal band
will continue to steadily move inland through 00Z, followed by a
lull in precipitation intensity outside of instability driven
showers due to steepening mid-level lapse rates tied to the
approach of the closed low aloft. RAP forecasts show MLCAPE up to
~500 J/kg along the OR coast through the early overnight.

As the deep low level low nears the coast, a period of strong 850
mb onshore flow is expected to be directed into the coast of
northern OR into southern WA, with 850 mb wind speeds of 70-80 kt
in the 03-09Z time frame from the SW to WSW. While snow levels
will be dropping to ~3500 ft behind the cold front across the
Pacific Northwest, the u-component of the 850 mb wind will be
60-70 kt into the Coastal Ranges and 30-45 kt into the Cascades
with a strong orographic component and steady rainfall of 0.2 to
0.4 in/hr, locally up to 0.5 in/hr possible.

While rainfall rates will not be exceptionally high, the addition
of 1 to 2 more inches, perhaps as high as 3 inches through 08Z, is
expected. Due to widespread 3 to 6 inch rainfall totals across the
region over the past 48 hours, additional rainfall may bring
additional localized concerns for runoff problems including small
stream and urban flooding.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!55bhW1vo4IQzGsDuIMw_NE5Diu18eoFsJYr2p46l6W9gZLhpJIff3SS_BrqRHC7dYc7W= TAHvAhW86MrVVwQRIVZuG1s$ for graphic product...

ATTN...WFO...PQR...SEW...

ATTN...RFC...NWRFC...NWC...

LAT...LON 47912425 47842399 47612365 47572333 47602310=20
47032293 46942263 47022225 46962195 46652177=20
46332188 45982181 45652168 45362178 44972186=20
44622201 44442224 44442248 44492262 44712279=20
44852288 44902310 44862327 44742334 44652339=20
44492349 44402379 44472410 44582428 44962430=20
45732423 46472429 47062450 47622455 47802452=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 250750
FFGMPD
ORZ000-WAZ000-252000-

Mesoscale Precipitation Discussion 0052
NWS Weather Prediction Center College Park MD
250 AM EST Tue Feb 25 2025

Areas affected...Lower Foothills of Western Washington & Far
Northwest Oregon...

Concerning...Heavy rainfall

Valid 250800Z - 252000Z

SUMMARY...Reducing rainfall rates to .25-.3"/hr and spots of
additional 2-3" adds to streamflows/ongoing river flooding within
western facing foothills of Cascades/Olympics, as well as much of
the Coastal Range.

DISCUSSION...GOES-W WV shows an textbook symmetric deep layer
fairly broad cyclone just west of the entrance to the Juan de Fuca
strait, which is accompanied by a sub 985mb surface low. While
the cyclone is starting to fill well past peak maturity, a subtle
lobe of vorticity and associated jet streak is rounding the base
of the cyclone resulting in broadening diffluent/divergent
downstream flow across W WA increasing westerly surface to 700mb
flow. Given onshore surface winds are gusting over 50 mph that
increase to 70kts by 700mb slowly veering from WSW to W over the
next few hours, is solidly orthogonal to the SW slopes of the
Olympics and while moisture is limited due to the deep cold air
through depth, total PWats of .75" and the strength of winds will
continue to result in solid rainfall rates of .25 to .3"/hr in the
lower slopes before the freezing levels about 3Kft.=20

The upper-low will continue to spin down but approach the coastal
range maintaining the strong moisture flux with very slow
reduction with the winds. The Willapa Hills will take the
greatest brunt of flux closer to the track of the low and best
orthogonal flow to support .25-.3"/hr for about 9-12 hours which
will allow for an additional 2-3"+ though spots along the NW
Oregon Coastal Range in Clatsop and Tillamook counties will see
slightly reduced rates, but still potent for 1-2.5" totals. Given
soil conditions are already nearly fully saturated per NASA SPoRT
LIS product suggesting 85-95% saturation through 40cm, most will
continue to run off and maintain already increased stream rates
and flooding conditions in downstream rivers, yet rates are not
likely to result in rapid rises.

Downstream into the Cascades, the slopes increase rapidly with
only limited areas of the lower foothills below freezing levels,
with much of the moisture above to fall as snow. Still, similar
1-3" totals in the lower foothills extend mainly north of the
Columbia river in the Washington Cascades with best rates up to
.25"/hr likely as the core of the upper-level low crosses later
this morning into early afternoon (15-20z), ending the prolonged
atmospheric river event.=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6ptxx-izneKiuT-T8bFrjZRyS9DoqHxEXlQ07Odyat_BSgRIPD4ILhc2sCWd-4sVOrHW= _qSY2GUrh7Sqs3iNsogBibM$ for graphic product...

ATTN...WFO...PQR...SEW...

ATTN...RFC...NWRFC...NWC...

LAT...LON 48942200 48742184 48432150 47742151 47592157=20
47042186 46692232 46322237 46232248 46172269=20
45992307 45572326 44912345 44722383 45082410=20
46302409 47572444 48352474 48232423 47882394=20
47502371 47432326 46852323 46682282 46812275=20
47032231 47492197 48092192 48412207 48792219=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 090921
FFGMPD
FLZ000-GAZ000-ALZ000-091520-

Mesoscale Precipitation Discussion 0053
NWS Weather Prediction Center College Park MD
520 AM EDT Sun Mar 09 2025

Areas affected...Far Southern GA...FL Panhandle into Northern FL

Concerning...Heavy rainfall...Flash flooding possible

Valid 090920Z - 091520Z

SUMMARY...Locally training clusters of heavy showers and
thunderstorms this morning may result in isolated areas of flash
flooding.

DISCUSSION...The latest GOES-E IR satellite imagery along with
dual-pol radar shows clusters of heavy showers and thunderstorms
gradually expanding in coverage across portions of the central and
eastern Gulf Coast region as southerly warm air advection and
moisture transport interacts with a quasi-stationary front
extending east from a wave of low pressure just east of New
Orleans, LA. A modest low-level jet of 20 to 30+ kts is focused
out ahead of this low pressure wave, with the primary nose of this
situated up into the FL Panhandle region where PWs are gradually
increasing along with instability.

MIMIC-PW data shows the pooling of 1.5 to 1.75 inch PWs currently
near the central Gulf Coast with the latest RAP analysis showing
MUCAPE values of 500 to 1000+ J/kg. However, the 3-hour MUCAPE
differentials are on the order of +400 to +600 J/kg across far
southern AL through the western part of the FL Panhandle and this
is where some of the more organized clusters of convection have
been developing over the last couple of hours.

As a positively-tilted mid-level trough and associated closed low
continues to eject east out of the southern Plains and toward the
Lower MS Valley this morning, there will be a gradual increase in
downstream upper-level divergence along with a corresponding
subtle increase in the low-level jet. This coupled with proximity
of the front across especially the FL Panhandle vicinity should
help facilitate a further expansion and organization of convection
in a general west to east fashion which will bring a concerns for
locally training showers and thunderstorms.

The HRRR has been generally trending wetter over its last few
model runs, and the HRRR coupled with the 00Z NSSL-MPAS guidance
support rainfall rates of 1 to 2 inches/hour, with sufficient
levels of cell-training to generate totals of as much as 3 to 5
inches by late this morning. These rains will be falling over
areas that are relatively dry based off the latest NASA SPoRT soil
moisture data, but given some of the wetter model trends overnight
along with the latest radar and satellite data, it will be
possible that enough rain falls this morning for some isolated
areas of flash flooding.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7cN8Er7gbxvXCCMp6l_QuyuQC4cX6fjOzVtsEC9BrtCMgIaUDHU75Hlm2yR0n6uZcY5p= jO9Ed7vKZG3lOUDkT_h6eM8$ for graphic product...

ATTN...WFO...JAX...MOB...TAE...

ATTN...RFC...SERFC...NWC...

LAT...LON 31198337 31148199 30858134 30458130 30138148=20
30008205 29898300 29848401 29668506 29908550=20
30268609 30308699 30608721 30878690 31038587=20
31088475=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 091534
FFGMPD
FLZ000-GAZ000-ALZ000-092132-

Mesoscale Precipitation Discussion 0054
NWS Weather Prediction Center College Park MD
1133 AM EDT Sun Mar 09 2025

Areas affected...portions of north Florida/Florida Panhandle and
southern Georgia

Concerning...Heavy rainfall...Flash flooding possible

Valid 091532Z - 092132Z

Summary...Flash flood potential should continue through 21Z/5p EDT
today as showers and thunderstorms repeat over areas that have
received 1-2.5 inches of recent rainfall.

Discussion...The flash flood risk across northern Florida and
adjacent areas of southern Georgia continues. Latest radar mosaic
imagery indicates scattered coverage of thunderstorms moving from
west to east along an axis extending from near Pensacola to near
Jacksonville. This axis is collocated with a nearly stationary
baroclinic zone, with localized ascent along that axis occurring
along the nose of 25-30 knot low-level jet centered over the
north-central Gulf just southeast of New Orleans. Flow aloft
remains parallel to the axes of convergence/heaviest rainfall,
supporting continued training/repeating convective activity.=20
Moist thermodynamic profiles (1.5+ inch PW) and elevated
instability (around 1000 J/kg MUCAPE) continue to support robust
updrafts with local rain rates of 1-2 inches/hr at times beneath
training convection.

The ongoing meso-to-synoptic scale pattern supporting heavy rain
is expected to persist through at least 21Z today. Some question
exists regarding convective coverage given slight ridging aloft
ahead of a positive tilt mid-level wave centered over northeast
Texas, although general consensus (supported by models and
observations) is that enough convective coverage will continue to
foster training and occasional 1-2 inch/hr rain rates. Some of
these rates will fall on wet soils from prior rainfall over the
last 3-6 hours, promoting localized runoff. Localized totals
exceeding 3 inches through 21Z cannot be ruled out.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9veAP3tFSullh2E8hoKhzT9euHwmG4wO47cksP5TLNtUOWzbVzVBVgWg_cmH-SvF-0TY= 1W2gmBPKbK-f1DuzgWUk08Q$ for graphic product...

ATTN...WFO...JAX...MOB...TAE...

ATTN...RFC...SERFC...NWC...

LAT...LON 31488330 30958141 29928135 29718329 29818531=20
30188715 30888635=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 092135
FFGMPD
FLZ000-GAZ000-100334-

Mesoscale Precipitation Discussion 0055
NWS Weather Prediction Center College Park MD
535 PM EDT Sun Mar 09 2025

Areas affected...northern Florida and far southern Georgia

Concerning...Heavy rainfall...Flash flooding possible

Valid 092134Z - 100334Z

Summary...Scattered convection continues to pose an isolated flash
flood threat while migrating eastward across the discussion area.=20
Another 1-3 inches of rainfall are possible through 03Z/11p EST
tonight.

Discussion...Over the past couple hours, a gradual uptick in
convective coverage has been noted across the western and central
Florida Panhandle. This increase in convective coverage is likely
tied to a few factors, including: 1) subtle geopotential height
falls ahead of an advancing mid-level wave near the ArkLaTex, 2)
the inland advection of warm/moist air that can support more
surface-based convection, and 3) continued convergence on the nose
of 30-kt southwesterly low-level flow over the central Gulf. The
increase in coverage along with modest training/repeating has
resulted in a few areas of 3 inch rainfall totals since 15Z, with
much of that tally happening in a 2-hour window. Rainfall was
wetting soils and resulting in lower FFG thresholds especially in
and north of the I-10 corridor in the central Florida Panhandle
(near the Tallahassee area). These factors suggest an uptick in
flash flood potential in the short term.

The meso-to-synoptic scenario should continue to foster areas of
heavy rainfall through 03Z. Deep moist convergence should remain
focused along the Florida Panhandle for the next 3-6 hours as
forcing for ascent associated with the mid-level wave approaches
the region. Additional convection should migrate eastward into
southeastern Georgia and northeastern Florida over time.=20
Localized 3 inch totals through 03Z remain possible beneath
training/repeating convective axes. Isolated instances of flash
flooding are expected as a result.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_pKdQfdqHQpCQEiJRYXMfLh5ME0F9tG0zNqyX7FtHfalbr71_61zH2ofmEpr8FlJPm3T= b4NWA5vtjXA2crJClLNNs-Y$ for graphic product...

ATTN...WFO...JAX...TAE...

ATTN...RFC...SERFC...NWC...

LAT...LON 31318282 30958161 29748222 29658522 29978586=20
30658635 30988469=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 100301
FFGMPD
FLZ000-GAZ000-100900-

Mesoscale Precipitation Discussion 0056
NWS Weather Prediction Center College Park MD
1100 PM EDT Sun Mar 09 2025

Areas affected...Southern GA...FL Panhandle to Northeast FL

Concerning...Heavy rainfall...Flash flooding possible

Valid 100300Z - 100900Z

SUMMARY...Locally training showers and thunderstorms are forecast
to continue into the overnight hours with additional concerns for
flash flooding.

DISCUSSION...The latest radar imagery shows a band of very heavy
showers and thunderstorms impacting the Big Bend of FL through
northeast FL, with an emphasis over the last couple of hours on
parts of Dixie, Lafayette and Taylor Counties. The convection is
well aligned with a quasi-stationary front draped across the
region and is being driven by focused low-level moisture
convergence and the pooling of instability ahead of a wave of low
pressure transiting the northeast Gulf of America. Meanwhile,
scattered bands of heavy showers and thunderstorms are also seen
redeveloping across areas of the FL Panhandle and up across
southern GA to the north of this front.

PWs of 1.5 to 1.75 inches are in place along the front along with
MUCAPE values of about 1000 J/kg. There is a southwest low-level
jet of 30 to 40 kts helping to favor the moisture and instability
transport, and with rather divergent flow aloft noted out ahead of
an approaching mid-level trough, there should continue to be a
focus well into the overnight hours for additional showers and
thunderstorms that should generally track in a west-southwest to
east-northeast fashion.

Overall, the heaviest rainfall threat at least for the next few
hours should continue to be in vicinity of the Big Bend of FL, but
areas downstream toward northeast FL including the greater
Jacksonville area may also potentially see additional heavy
rainfall amounts from some of these stronger showers and
thunderstorms. The 00Z HREF guidance also maintains a threat for
locally heavy rains across southern GA with sufficient levels of
elevated instability and forcing expected to remain in place for
additional small-scale bands of convection going into the
overnight hours.

Rainfall rates with the stronger storms will be capable of
reaching 1.5 to 2 inches/hour, and additional rainfall totals
overnight may reach as high as 3 to 4+ inches. This will yield an
additional concern at least locally for flash flooding, with the
more urbanized locations generally at greatest risk for seeing
impacts.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!60T8bdQo2_4hnlREzM4XsNH5K2rP0jLfF4D4-Hd1fZoYSH2SQjr2N3nsTqziOKd2MLx1= 3GjvRChr80iSTGYGciAjIYk$ for graphic product...

ATTN...WFO...CHS...JAX...TAE...TBW...

ATTN...RFC...SERFC...NWC...

LAT...LON 31858202 31708113 31338105 30808125 29938125=20
29748153 29508198 29408313 29848371 29908454=20
30298508 30988488 31638356=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 112021
FFGMPD
CAZ000-120215-

Mesoscale Precipitation Discussion 0057
NWS Weather Prediction Center College Park MD
421 PM EDT Tue Mar 11 2025

Areas affected...Coastal Southern California...Eastern Channel
Islands....

Concerning...Heavy rainfall...Flash flooding possible

Valid 112020Z - 120215Z

SUMMARY...Convective elements capable of .5-.75"/hr rates and
totals up to 1" pose localized possible flash flooding conditions
particularly in urban/rocky sloped ground conditions.

DISCUSSION...GOES-W Visible imagery continues to show a band of
convective cells along the northeast quadrant of the deep layer
cyclone. An embedded lobe of vorticity is rounding the southern
base of the low providing subtle but sufficient diffluence aloft
across the southeastern California Bight with slowly increasing
DPVA to further enhanced vertical development. WV suite also
suggests core of upper-level low and cold air advection is
filtering in steepening the lapse rates with MUCAPE reaching
500-750 J/kg within the band. Low level confluent response along
the band and ample surface to 850mb of .5-.6" per CIRA LPW
combines to support .75-.9" total PWats within/below the
steepening lapse rates. Cells have a healthy cauliform appearance
with boiling overshooting tops along the upstream edge; given
helicity of 100 m2/s2 and sfc-1km shear in the 15-20kt range, weak
rotation may be further supporting moisture flux into the cores of
the cells as they advance northeastward. Given all the
parameters, cores of the cells will be capable of .5-.75"/hr
rates.

The uncertainty will continue to be the intersection with land
areas before the window of opportunity reduces as the vorticity
center rotates through reducing effective ascent pattern in
3-6hrs. In the short-term, the upstream forcing should allow for upstream/back-building of cells slowing forward propagation, but
once the DPVA passes through, cell motions could increase to
20+kts, limiting totals. As such, cell cores are likely to
intersect San Clemente, potentially far eastern Catalina islands
with chance of up to 1" totals (HREF probs of 20-25%); however,
there is greater uncertainty toward reaching Orange county and
eastern San Diego county. Still, if cell maintain convective
vigor (as suggested by recent HRRR and RAP solutions), even .5"/hr
rates would be near the FFG values in the area; so while localized
scattered incident or two of flash flooding is considered possible
through 03z.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9QwItwWK0CVQJx-eQ_IvljRdXm0E8e-F73XKWm_oZYUC3P-ZmiyPEvotO0L2UdoN3B3m= L524sOk8LPxPbnuSN_ux3gQ$ for graphic product...

ATTN...WFO...LOX...SGX...

ATTN...RFC...CNRFC...NWC...

LAT...LON 33831750 33681704 33201664 32611654 32351696=20
32301741 32611822 33091863 33781836=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 121546
FFGMPD
CAZ000-130300-

Mesoscale Precipitation Discussion 0058
NWS Weather Prediction Center College Park MD
1145 AM EDT Wed Mar 12 2025

Areas affected...Northwest to Central California...

Concerning...Heavy rainfall

Valid 121545Z - 130300Z

SUMMARY...Progressive cold front/moisture flux to produce 1-2"
totals in 4-6 hours, particularly only coastal ranges and lower
foothills of the Sierra Nevada Range.=20

DISCUSSION...GOES-W WV suite depicts a broad cold larger scale
trough across the northeast Pacific with a leading northwesterly
surge of colder air undercutting the base generally a degree or
two south of the 40N130W benchmark. This is resulting in some
negative tilt to the base of the trof with downstream responses
noted in the expanding baroclinic shield cloud in the diffluence
aloft to the northeast nearing Cape Mendocino. This is starting
to buckle the surface front and enhanced surface to low level
cyclogenesis near 39N and 127W backing low level flow and
increasing the low level jet to 50kts within the broader
isentropic ascent into the upper-level evacuation zone. Total
moisture is not particularly impressive with this atmospheric
river with surface to 850mb CIRA LPW in the .5" range, however,
the narrow ribbon of mid to upper-level moisture is fairly
vertically aligned along/ahead of the cold front to support
reduced drying and perhaps some seeding from the mid-levels to
keep RH values higher than average in the band.

Still, the cold air advection is solid/strong resulting in a
fairly progressive frontal zone push from west to east. Initial
core of the pre-frontal LLJ is starting to interact with the
Lost/Redwood near and south of Cape Mendocino. The surface low
will track throughout the period into the Cape region and
potentially allow for additional surges of steepening lapse rates
for secondary convergence bands with weaker/narrow updrafts
intersecting the coastal region through the remainder of the day.=20
Rates should remain at or below .5"/hr averaging around .25" and
support 1.5-2.5" totals in favored orographics, but will come of
little concern given the rain forest nature to the area. However,
as the cold front presses through, strong 40-50kts of flow will
intersect the coastal ranges toward the San Francisco bay through
21z. As the cyclone continues to deepen, the directional
convergence along the front will go from 30-45 degrees up to 60-75
degrees increasing the overall convergence. The undercutting
upper-level shortwave may also have some peripheral influence of
steepening lapse rates aloft for some increased vertical ascent to
these convergence/ascent parcels allowing for narrow scattered
updrafts along the front with .25 to locally/occasionally reaching
near .5"/hr with 12z HREF .5"/hr probability values vacillating
around 30-50% changes north of the Bay through 21-22z time period.
=20

...Central Californian coasts/Central Valley...
As the front drops south past the San Francisco Bay, the winds
will continue to be strong but also orient more favorably to the
Santa Cruz and eventually Santa Lucia ranges with near
orthogonality through solid depth in the 21-00z time period. The
IVT strength will be peaking toward 500 kg/m/s with 850-700mb flow
starting to weaken slightly due to displacement southward from the
peak cyclogenesis...but still in the 40-50kt range. The
combination of flux to steeper terrain will result in .5"/hr rates
being more likely, but given the southward translation of the cold
front may only result in 1-3 hours and overall totals are more
likely to be near 2-2.5", but an isolated 3" is not completely out
of the picture. HREF probability is over 80% for much of the
period along the Santa Lucia from 23-02z, though never even
reaches 10% for 1"/hr.

The moisture surge will have also filtered through the lower
terrain gap of the Bay and shower activity will also likewise
increased through the central valley into the lower foothills of
the Central Sierra Nevada. Similarly, favored, nearly orthogonal
ascent will support .25-.33"/hr rates. Totals of 1.5-2"+ may
result in increased runoff, but more likely beneficial in all but
the most prone areas. Forward progression will continue with the
front, likely reaching Southern California/Cape Conception after
03z.=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9wSFTaHPHgEaMtQ9LPhHbeJKNAuzNgnahkhk9ORXzVDu2-Q_CtdDGjTbt-TAXv5Z1HW4= _dyWAy9m8u6k0of2KtDHU0U$ for graphic product...

ATTN...WFO...EKA...HNX...LOX...MTR...STO...

ATTN...RFC...CNRFC...NWC...

LAT...LON 41272379 40622330 40412284 40062178 39442086=20
38272024 37511972 36702069 35812059 35162041=20
34582037 34442061 35362112 36182194 37652263=20
38432348 38782376 39122387 39692401 40072450=20
40822442 41202419=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 130205
FFGMPD
CAZ000-131405-

Mesoscale Precipitation Discussion 0059
NWS Weather Prediction Center College Park MD
1005 PM EDT Wed Mar 12 2025

Areas affected...portions of southern California

Concerning...Heavy rainfall

Valid 130205Z - 131405Z

Summary...A frontal band will translate from west to east across
southern California coastal ranges, resulting in 1-2 inch rainfall
totals - highest in terrain-favored areas. This rainfall will
affect burn scars across the region, posing a risk of runoff,
flash flooding, and debris flows through at least 13Z/6a PDT.

Discussion...A strong Pacific cold front (currently located near
KPRB/Paso Robles, CA and KSBP/San Luis Obispo) was making steady
southeastward progress over the past several hours, and will
continue to do so across the discussion area through 13Z. Along
and west of the front, areas of convection have produced 0.5-1
inch of rain over the past 3 hours - highest along coastal areas
between San Francisco and San Luis Obispo within the Santa Lucia
Range. Minor flooding has also occurred across Alameda County.
These rainfall rates will continue to spread southeastward in
tandem with the front, while potentially increasing as depicted by
CAMs as the rainfall band reaches the Transverse Ranges and
adjacent areas near Los Angeles Metro through 06-12Z (11p-5a PDT)

As these rates spread southeastward, they will encounter fresh
burn scars from recent fires across the region. These and other
sensitive areas will promote runoff along with the potential for
flash flooding and debris flows. Models/obs indicate that a 3-5
hour period of moderate to heavy rain will affect the region, with
peak flash flood risk potential occurring in the 08Z-12Z (1a-5a
PDT) timeframe around the Los Angeles metro and adjacent areas of
the Tranverse Ranges. The risk will peak farther southeast toward
San Diego and adjacent mountainous areas in the 12-14Z (5a-7a PDT)
timeframe. Storm totals of 1-2 inches are expected (locally
higher in terrain-favored areas), and peak hourly rain rates
should mostly remain in the 0.5-0.75 inch range, locally higher.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9l63Z6R_esTVdrCecbqOAtG3lr6pabvSCrQmDjG1DDk7QWEkBZ39gano74qcppqcUoRa= xE81mbjsCZVb5r5_TWGABXY$ for graphic product...

ATTN...WFO...HNX...LOX...SGX...VEF...

ATTN...RFC...CNRFC...NWC...

LAT...LON 35732024 35711942 35461831 35081719 34491661=20
33541642 32851661 32601709 32941746 33571821=20
33871899 34142000 34632080 35342090=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 150824
FFGMPD
ALZ000-MSZ000-151122-

Mesoscale Precipitation Discussion 0060
NWS Weather Prediction Center College Park MD
423 AM EDT Sat Mar 15 2025

Areas affected...northeastern Mississippi and northwestern Alabama

Concerning...Heavy rainfall...Flash flooding possible

Valid 150822Z - 151122Z

Summary...Localized 1.5-2.5 inch/hr rain rates should continue for
the next couple hours or so. Convective evolution thereafter is a
bit uncertain. Isolated flash flooding is possible.

Discussion...A dominant, right-moving supercell has persisted for
several hours while reaching Itawamba County, Mississippi near the
MS/AL border. This supercell has maintained broad rotation within
a moist and strongly sheared airmass. Convection immediately
upstream (along and north of its gust front) has enabled a
scenario for localized training and rain rates approaching 2
inches/hr from near Okolona, MS northeastward to near Fulton, MS.

As his lead supercell progresses into Alabama, increasing
convective coverage has materalized upstream in areas near Tupelo,
Columbus, and Greenwood. The cells are embedded within strong,
broadly confluent 850mb flow exceeding 45 knots areawide, which
continues to maintain moist/unstable thermodynamic profiles in the
immediate wake of the supercell. It appears that this confluent
low-level jet structure should be maintained for mutliple hours
this morning despite 1) departing forcing for ascent with a
mid-level vort max moving away toward the upper Midwest and 2)
renewed mid-level troughing across Texas that should result in a
gradual backing of 850mb flow.

The ongoing supercell along the MS/AL border should eventually
weaken as it reaches less stable air especially across north-central/northeastern Alabama. Upstream convection, however,
should continue to support localized runoff issues as 1-hour FFG
thresholds (in the 1.5-2 inch range) are approached by localized repeating/training cells across the discussion are through the
morning - especially in areas that have already had rainfall.=20
Isolated flooding is possible, although this event appears to be
perhaps the beginning of a more synoptically evident flash flood
event expected to unfold later today/tonight.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7eCMpjSSgxklFtbZy5khg8whhCUDdbCxFysQ5KngdLyj_VimEKCIqmbL2B7FmnAwhFAD= 7iMELL4PgcC3C1toe7e7W1s$ for graphic product...

ATTN...WFO...BMX...HUN...JAN...MEG...

ATTN...RFC...LMRFC...SERFC...NWC...

LAT...LON 34998775 34638646 34078673 33678809 33918976=20
34758916=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 150838
FFGMPD
ALZ000-MSZ000-151122-

Mesoscale Precipitation Discussion 0060
NWS Weather Prediction Center College Park MD
437 AM EDT Sat Mar 15 2025

Areas affected...northeastern Mississippi and northwestern Alabama

Concerning...Heavy rainfall...Flash flooding possible

Valid 150822Z - 151122Z

Summary...Localized 1.5-2.5 inch/hr rain rates should continue for
the next couple hours or so. Convective evolution thereafter is a
bit uncertain. Isolated flash flooding is possible.

Discussion...A dominant, right-moving supercell has persisted for
several hours while reaching Itawamba County, Mississippi near the
MS/AL border. This supercell has maintained broad rotation within
a moist and strongly sheared airmass. Convection immediately
upstream (along and north of its gust front) has enabled a
scenario for localized training and rain rates approaching 2
inches/hr from near Okolona, MS northeastward to near Fulton, MS.

As this lead supercell progresses into Alabama, increasing
convective coverage has materalized upstream in areas near Tupelo,
Columbus, and Greenwood. The cells are embedded within strong,
broadly confluent 850mb flow exceeding 45 knots areawide, which
continues to maintain moist/unstable thermodynamic profiles in the
immediate wake of the supercell. It appears that this confluent
low-level jet structure should be maintained for multiple hours
this morning despite 1) departing forcing for ascent with a
mid-level vort max moving away toward the upper Midwest and 2)
renewed mid-level troughing across Texas that should result in a
gradual backing of 850mb flow.

The ongoing supercell along the MS/AL border should eventually
weaken as it reaches less stable air especially across north-central/northeastern Alabama. Upstream convection, however,
should continue to support localized runoff issues as 1-hour FFG
thresholds (in the 1.5-2 inch range) are approached by localized repeating/training cells across the discussion are through the
morning - especially in areas that have already had rainfall.=20
Isolated flooding is possible, although this event appears to be
perhaps the beginning of a more synoptically evident flash flood
event expected to unfold later today/tonight.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4kA5R-nTAYdqcnuZSVxKc7CLoymXMlueBEuDFgRhC6J5yx9FvJI17HxkWFUVMzJXfnS9= bmsX-xqX1Sl_gXjmZScFA6k$ for graphic product...

ATTN...WFO...BMX...HUN...JAN...MEG...

ATTN...RFC...LMRFC...SERFC...NWC...

LAT...LON 34998775 34638646 34078673 33678809 33918976=20
34758916=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 151130
FFGMPD
TNZ000-MSZ000-LAZ000-ARZ000-151700-

Mesoscale Precipitation Discussion 0061
NWS Weather Prediction Center College Park MD
730 AM EDT Sat Mar 15 2025

Areas affected...Northern Louisiana, Northwestern Mississippi, &
Western Tennessee

Concerning...Heavy rainfall...Flash flooding likely

Valid 151129Z - 151700Z

SUMMARY...Training cells along a stationary upper level boundary
will likely pose a flash flooding threat through the morning with
rates locally exceeding 2 inches per hour. Flash flooding is
likely.

DISCUSSION...A very dynamic scenario is unfolding across
northwestern Mississippi this morning as a stationary upper level
boundary acts as a forcing mechanism for storms that are already
forming. Low level SSE flow is advecting plentiful Gulf moisture
characterized by dew points near 70 degrees and SBCAPE values over
2,000 J/kg into the region. At 850mb, a south-southwesterly LLJ
has strengthened to near 50 kts, which will keep a steady supply
of moisture advecting into the front. Meanwhile a potent shortwave
across northeast Texas is approaching the region, which will add
even more forcing. This will both strengthen the storms training
along the front and broaden the precipitation shield over the
area, meaning many areas will not see a break in the rainfall.

1-hr FFGs in this region are generally between 1.5 and 2.5 inches,
which will both come down with the early morning convection
already breaking out, and with the later additional forcing will
support even stronger convection capable of rates exceeding 2
inches per hour. This will support widely scattered to numerous
instances of flash flooding across this region. Despite recent dry
weather, the long-duration of the training convection across this
region should easily overcome these FFG values. While each
individual cell will move rather rapidly to the northeast across
this area, the high likelihood that multiple cells producing heavy
rainfall will move over any one location under the line of storms
will compound any flooding and rises in streams and creeks rather
rapidly.

Urban flash flooding will be a significant concern as these storms
set up very near metro Memphis, though likely staying just south
and east of the city. Expect the southern and eastern suburbs to
be hard-hit with multiple inches of rain through the morning.

The line of training storms is likely to remain in roughly the
same place through the morning based on many of the CAMs guidance
into the early afternoon until both the upper level shortwave and
attendant surface cold front push through and shift the storms off
to the east. This discussion will be updated as the situation
evolves.

Wegman

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_5HHhRDdgRo8t5NqeiouNdOmh4EPxcRsY94ub6gJ8DUkOHw5DL79hu5sOW6OO7mB_JwL= PHDjrB-y_X0F9KE_5RWUGcg$ for graphic product...

ATTN...WFO...JAN...LZK...MEG...OHX...SHV...

ATTN...RFC...LMRFC...OHRFC...SERFC...NWC...

LAT...LON 36408824 36138749 35118829 34788860 34038936=20
31619205 31649320 32649244 33719163 34739068=20
36118922=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 151321
FFGMPD
GAZ000-TNZ000-ALZ000-151630-

Mesoscale Precipitation Discussion 0062
NWS Weather Prediction Center College Park MD
920 AM EDT Sat Mar 15 2025

Areas affected...Northeastern Alabama, Far Northwestern Georgia,
and Southeastern Tennessee

Concerning...Heavy rainfall...Flash flooding possible

Valid 151319Z - 151630Z

SUMMARY...Training cellular convection over northeastern Alabama
may cause a localized flash flooding risk as they advect
northeastward into the Chattanooga Metro.


DISCUSSION...Cellular convection that has been largely stationary
across northeastern Alabama this morning has been advecting
northeastward into the Chattanooga Metro area this morning.
Southeasterly surface flow characterized by dewpoints in the 50s
is largely orthogonal to the northeastward moving and oriented
line of convection. This has been feeding the storms and
contributing to their persistence. The upper levels feature a
bifurcated jet streak, with the storms in the middle of the
bifurcation. It's possible the southern arm is contributing to
upper level lift being in the divergence region of the jet.

Much of the CAMs guidance suggests this area of storms will shift
off to the north and join up with the line of storms well to its
west over the next few hours. However, that remains to be seen, as
the forcing would support the storms remaining in place. Following
a persistence forecast, over the next few hours, heavier cells
will be moving over the Chattanooga metro, which due to urban and
terrain concerns poses a higher localized flash flooding risk.
Most of the instability is west of the storms, with the
southeasterly inflow not advecting much into the storms. Thus,
there is some chance the storms fall apart on their own, but as
that hasn't happened yet, the flash flooding threat will persist
for the next few hours. At the very least, this offset of
instability from the inflow should continue to limit the strength
and maximum rainfall potential of the storms.

Wegman

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8mgvyMuJcn2-fNlM-3kPTK3NR5GcSLFrpfLYhsaijjuto0MX9J5U-5AtZQgL05dJGAt9= MxvhoQMMFQID5WhjD9kgCDg$ for graphic product...

ATTN...WFO...BMX...FFC...HUN...MRX...OHX...

ATTN...RFC...LMRFC...OHRFC...SERFC...NWC...

LAT...LON 35748504 35588457 35168472 34748494 34158542=20
34048613 34088651 34828709 35388651=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 151644
FFGMPD
TNZ000-KYZ000-ALZ000-MSZ000-LAZ000-152230-

Mesoscale Precipitation Discussion 0063
NWS Weather Prediction Center College Park MD
1244 PM EDT Sat Mar 15 2025

Areas affected...Northern MS...Northwest AL...Western to Middle TN...South-Central KY...

Concerning...Heavy rainfall...Flash flooding likely

Valid 151645Z - 152230Z

SUMMARY...Strong, highly efficient rotating thunderstorms capable
of 1.5-2"/hr rates likely to train for a hour or so as the line
slowly advances eastward. Subtle buckles in the QLCS may result
in further enhanced duration with a spot or two of 4-5" possible.=20
Rates and totals are likely to result in scattered to numerous
incidents of flash flooding to accompany severe weather risk.

DISCUSSION...GOES-E WV suite depicts secondary upper-level low
deepening across OK/N TX with lower scale shortwave resulting in
some negative tilting. This results in broadening of dual jet
structure with very impressive downstream baroclinic shield across
the Mid-MS Valley into Lower Ohio Valley denoting the very strong
divergence aloft, especially in proximity to 130kt 250H jet streak
exiting over N IL into LP of MI. The wedge of diffluence across
the area of concern will provide strong large scale ascent to
maintain the well above average low level wind flow; 850mb 50-65kt
southerly with backed sfc to boundary layer 20+ kt flow pumping
higher theta-E air across E MS/AL into southern Middle TN with Tds
increasing from low 60s to upper-60s/low 70s. Mid-level EML has
been mixing out, but has allowed for increasing unstable air mass
(2000-2500 MLCAPE) along the sharp pre-frontal pressure trough
from W TN back to a developing surface wave in NE LA. Overall the
strength of the low level flow and solid low level moisture (up to
1.5" TPW) resulting in highly anomalous flux values near 3-3.5 Std
Dev from normal and generally about 1000+ kg/m/s of IVT.

As such, very strong, broad and likely rotating updrafts will
further enhancing localized moisture flux due to isallobaric flow
but also strong convergence to add about .5"/hr to general
updrafts. WoFS solutions continue to have many of the runs
supporting .3-.5"/5 minute rates with this broader cores allowing
for increased duration and hourly totals of up to 2"/hr. So any
given storm may overwhelm urban/prone flooding locations even if
isolated or along/ahead of the main line. The greater concern,
particularly further north where deeper mean flow will allow for
more of pivot point to develop for the longer line of cells,
should increase potential for SW to NE training convection,
especially near/downstream of the surface wave as it lifts from NE
LA across central MS to Middle TN.

Current surface observations and RADAR mosaic suggest a weak
WAA/isentropic boundary across south-central Middle TN eastward
toward the southern Cumberland Plateau due to earlier convection.
WoFS, HRRR and RAP rapidly refreshing guidance all suggest, this
boundary will maintain with a buckle noted in the SB/MLCAPE fields
though MUCAPE will support elevated convection downstream across
northern Middle TN into south-central KY. As such, this
inflection near the MS/TN/NW AL border continues to be highest
potential for those longer duration/training events with 4-5"
totals possible through 22z...slowly lifting northeastward across
Middle TN into the later evening hours. This also overlaps with
rainfall reduced FFG values and will likely result in scattered to
numerous incidents of flash flooding this afternoon into early
evening. Scattered incidents are likely further north into KY
where FFG and instability are lower; as well as south into central
MS where cells will be stronger, but duration is likely to be
lower and FFGs a bit higher.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6ZunH1fZ5lizEHjEz_LL0-V-fh5nX6MlqJl6Dj25tXUpVt2WUpoBFRZ_K2-GwNxLW1QR= LIf3igJylnBuPn6SlBJ0tf4$ for graphic product...

ATTN...WFO...BMX...HUN...JAN...LMK...MEG...OHX...PAH...

ATTN...RFC...LMRFC...OHRFC...SERFC...NWC...

LAT...LON 37528646 37418538 36678505 35748543 34328659=20
32888788 32158867 31798983 32109095 33489055=20
34948934 36448791=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 151850
FFGMPD
OHZ000-INZ000-152230-

Mesoscale Precipitation Discussion 0064
NWS Weather Prediction Center College Park MD
249 PM EDT Sat Mar 15 2025

Areas affected...Central and Eastern Indiana into Adj. Northwest
Ohio...

Concerning...Heavy rainfall...Flash flooding possible

Valid 151850Z - 152230Z

SUMMARY...A very narrow band of thunderstorms ideally oriented to
the moisture gradient and deep layer steering flow and of
sufficient length for training to exceed lower FFG values in the
region suggest an incident or two of localized flash flooding is
possible.

DISCUSSION...GOES-E WV overnight into early this morning noted the
strong cyclone across the Upper Great Lake region resulted in a
strong, elevated mixed layer (EML) extending well northwest into
the Ohio River Valley and central Great Lakes region, with
dust/soil and smoke particulates noted with it in the visible
imagery. This mixed layer has a surface reflection noted by a
frontal/dewpoint gradient across central IL into NW IND, with 40s
quickly becoming upper 50s and mid 60s across central and southern
IND. Clear skies this morning provided short-duration but ample
insolation for instability to build with SBCAPEs reaching near
1000-1500 J/kg mainly along and south of the boundary.

The WV suite also notes a broadening baroclinic shield of high
cirrus moving across the area associated with a broadening
diffluent region across the Ohio River Valley as a 130kt 250mb jet
streak continues to wrap along the interface of the older cyclone
and the approaching strengthening one from the Southern Plains.=20
This has provided strong divergence aloft along the broad right
entrance region of the jet and in turn lead to the acceleration
and backing of the low level jet across the TN Valley into the
region. Southerly winds intersecting with the SW to NE gradient
within the area of surface based instability provided sufficient
moisture convergence to generate thunderstorms along and south of
this axis within the area of deeper surface to boundary layer
moisture. Initial thinking was the cores of updraft would be
narrow given limited instability/surface heating. Strong steering
flow would also result in quicker SSW to NNE cell motion and the
probability of intersection of narrow updrafts would be limited.=20
However, recent trends note the stronger heating and moisture flux
convergence has resulted in slightly broader up/downdrafts while
also expanding longer along the convergence axis. Combined with
nearly parallel deeper layer steering and all 3 components are
start to result in a narrow axis of intense thunderstorms with
hourly rates of 1-1.5"/hr.=20

Given the length is about 80 miles, there is solid potential for
spots of 1.5-2" totals within 1-2 hours. FFG values are already
low from slower green-up with 1hr values between 1-1.5 and 3hr
values less than 2" along the training axis. As such, localized
flash flooding is considered possible, even if only a few
neighboring watersheds are impacted. The risk for flash flooding
is likely to be limited in time given quick erosion of remaining
downstream unstable area and may only exist for a few more hours
before weakening.=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_UivbsJzSPcg_k9OS7bFSpmk5XzP2UNVT1RHNVTblUqpFgwUKiN8sZnwlFcXLBFksmHQ= e5xLrnDHs6iNGoOdX9t6ecQ$ for graphic product...

ATTN...WFO...ILN...IND...IWX...

ATTN...RFC...OHRFC...NWC...

LAT...LON 41248449 40808418 39948506 38878650 39058701=20
40478589 41238521=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 152046
FFGMPD
FLZ000-ALZ000-MSZ000-LAZ000-160230-

Mesoscale Precipitation Discussion 0065
NWS Weather Prediction Center College Park MD
446 PM EDT Sat Mar 15 2025

Areas affected...Eastern LA...Southeast MS...Southern AL....

Concerning...Heavy rainfall...Flash flooding possible

Valid 152045Z - 160230Z

SUMMARY...Lines of rotating cells are starting to congeal into a
more single line and starting to advance eastward. Better
alignment of moisture and instability axis will retain moisture
flux to support up to 2"/hr rates; however, a more easterly
component may reduce some training and therefore flash flooding
will become more scattered in nature over higher FFG.=20

DISCUSSION...GOES-E WV suite depicts core of negative tilt
shortwave has swung through Arkansas into the middle MS valley,
this has resulted in low level veering and alignment of the
moisture and instability axis across E LA into S MS. Currently,
merging cells across the best confluence in S MS is resulting in
higher than average rainfall rates (to other cells) due to
slightly backed flow downshear of surface low near BTR. Moisture
flux of 20-25kts of low 70s Tds and 2000-2500 J/kg of MLCAPE will
maintain strong updrafts and efficient low level moisture flux
convergence for rates of 2"/hr, perhaps as high as 2.5-3" for very
short periods when isallobaric flow increases with cycling of updrafts/supercells.=20

Upper-level flow is starting to increase with overspreading of WSW
3H jet over 110kts, increasing easterly propagation component to
the convective line. This will reduce training in the longer
period, so supercells will continue to remain efficient along the
line with streets of 2-3" totals possible. Combined with the
generally higher FFG values across S MS/AL and E LA, flash
flooding should become more scattered/isolated in nature as the
line increases forward speed. However, there are numerous prone
urban centers, particularly along I-10 that may be quickly
over-whelmed by 1-2" sub-hourly totals if directly impacted by the
leading broad downdrafts. As such, flash flooding is considered
possible across the area of concern. An additional MPD will be
issued subsequent to discuss higher likelihood flooding conditions
further north.=20=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!47acq6U6UiFDtOn5lz9LnQ7bSRAEohWdHH8qHVXCHooew4f0BdlG2iwOFFw53xlugh5a= 2eMIAF4cfO_voMfiU4v6nrw$ for graphic product...

ATTN...WFO...BMX...JAN...LIX...MOB...

ATTN...RFC...LMRFC...SERFC...NWC...

LAT...LON 33398592 32748566 31788611 31128717 30488834=20
29839028 30519073 31999005 32718931 33318745=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 152129
FFGMPD
GAZ000-TNZ000-KYZ000-ALZ000-MSZ000-160315-

Mesoscale Precipitation Discussion 0066
NWS Weather Prediction Center College Park MD
528 PM EDT Sat Mar 15 2025

Areas affected...Middle & Eastern TN...Northeast MS...Northern
AL...Northwest GA...South-Central KY...

Concerning...Heavy rainfall...Flash flooding likely

Valid 152130Z - 160315Z

SUMMARY...Multiple lines of thunderstorms with moderate shield
precipitation between crossing already saturated/low FFG soil
conditions, likely to continue flash flooding risk through to
early overnight period.

DISCUSSION...A very complex surface pattern exists across the
middle MS Valley due to the back to back strong upper-level
shortwaves. This continues through depth with the EML from the
prior stronger closed low being modified by earlier convection
this morning across E TN/N MS; while a secondary dry slot is
starting to manifest across AR in the wake of the secondary
shortwave now maturing across S MO. As such, surface moisture
though worked over, remains across E TN/W KY/N MS with TDs still
in the upper 50s/lower 60s. However, strong LLJ in response to
the shortwave has allowed for the western branch of low level
moisture and warming at the boundary layer to wash through and
with steepening lapse rates from the new EML; an expanding area of
MUCAPE is developing across NE MS and W Middle TN in the wake of
the stronger cells further east. As such, there is an expectation
of the stronger forcing along the cold front and lifting surface
low across N MS to expand elevated thunderstorms along the leading
edge further into W Middle TN. MUCAPEs of 500-1000 J/kg will
increase over the next few hours and feed cells and given strong
low level moisture flux convergence allow for increasing rainfall
potential with 1-1.5"/hr rates possible. This is going to fall on
areas already saturated/flooded by earlier rounds of thunderstorms
(see below) and likely to exceed the compromised FFG values at or
below 1.5 at 1-3 hour time periods.

Ahead of this new development, the initial storms continue to
press eastward across E Middle TN into the Cumberland Plateau as
well as extending back as a pre-frontal convective line across N
AL and NE MS. A broad shield of moderate precipitation is likely
to continue between these two lines maintaining flooding
conditions through the late evening/early overnight period.=20=20
Cells to the east are starting to weaken a bit, with reducing
lightning mainly has area has only received advected higher
theta-E air from central AL/NE GA given cloud cover inhibiting
insolation throughout the day. Still, there is weak but
sufficient MUCAPEs into E TN and far S KY to maintain some. A
spot or two of 3-4" remains possible organization over the next
few hours. Rates of 1-1.5"/hr are probable given the broad,
strong LLJ pumping 1.5-1.75" TPW (mainly below 700mb) on 50+kts of
850mb southerly flow/WAA. As such, rainfall pattern will show
broad area of 2-3" across much of the eastern half of TN and
northern AL where multiple rounds will cross with embedded
weakening but intense showers to overtake those lower FFG
values/saturated soils in the region keeping flash flooding likely
through much of of the evening into early overnight period; but a
spot or two of 3-4" may result in considerable or even significant
flash flooding possible.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9BAOaS0GR8qN_Lw5l6zu_8ndMnqMO_QKRe3gr0a_a7eWDmIYEO2pGoZ15D8wpzhZB-H9= YbKfZSHxeuDjH6T-pjLeEpY$ for graphic product...

ATTN...WFO...BMX...FFC...HUN...JAN...JKL...LMK...MEG...MRX...
OHX...

ATTN...RFC...LMRFC...OHRFC...SERFC...NWC...

LAT...LON 37158440 36498387 35568421 34458484 33638532=20
33158642 32408895 32688965 33928905 35528824=20
36368765 36728673 37148538=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 152313
FFGMPD
CAZ000-ORZ000-160915-

Mesoscale Precipitation Discussion 0067
NWS Weather Prediction Center College Park MD
713 PM EDT Sat Mar 15 2025

Areas affected...Southwest Oregon...Far Northwest CA...

Concerning...Heavy rainfall

Valid 152315Z - 160915Z

SUMMARY...Persistent solid, relatively unwavering moist onshore
flow to bring average .25"/hr & up to .5"/hr rates; resulting in
localized totals of 4-5" in Coastal Range of SW Oregon and 2-3"
across lower slopes of southern Oregon Cascades.=20

DISCUSSION...GOES-W WV suite shows classically anti-cyclonically
curved strong upper-level jet with axis starting to near the
Oregon coast in the next hour or so. A highly sheared
vorticity/shortwave center along the northwest edge of the axis
will slide northeast into WA and leading nose of enhanced low to
mid-level moisture plume will reach the south-central to southwest
Oregon coastline. Winds will veer to SWly and increase from
40/45kts to 50-60kts by 03z. Visible imagery loop shows moisture
axis as well defined mid-level clouds with a line of enhanced, but
still shallow verticality that extends from near the ridge apex at
126W to 39N136.5W and 35.5N141W aligned with both the enhanced
moisture and surface to boundary layer convergence/confluence
axis. Very slow eastward advancement of the axis will retain
consistency in placement between N Coos to S Curry county in
Oregon for the next 9-12hrs. IVT values of average of 500 will
peak toward 750 kg/m/s throughout the late evening into early
morning hours. Combine this with favored orographic ascent will
allow for current .15-.25"/hr rates to increase to .33" to
occasionally .5"/hr rates in the SW OR boreal rain forest for that
duration.

This should result in localized 4-5" totals across SW Oregon,
while downstream, the moisture will be slightly reduced having
wrung out on the Coastal Range, but rates of .25-.33"/hr across
the Southern Oregon Cascades may allow for spots of 2-3" totals by
12z. This will be fairly focused and solid, given the location is
fairly accepting of these rainfall totals, increased run-off
should feed rivers but not likely result in rapid
run-off/inundation. As such, will leave this Atmospheric River as
Heavy Rainfall tag at this time.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5zSf8W_nkpEGKMSaxA5uhOGgHaTwtXSPZidNkJWNTvODKinYFpU2Mr5iSP1OoZab4pEn= BPgvyOul0YIfudJS1Vkn3OU$ for graphic product...

ATTN...WFO...EKA...MFR...PQR...

ATTN...RFC...CNRFC...NWRFC...NWC...

LAT...LON 44932234 44342219 43732228 43082226 42512226=20
42642271 42482332 41762335 41632368 41912437=20
42562454 43202456 43962431 44422419 44622389=20
44412352 44242311 44732266=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 160209
FFGMPD
GAZ000-ALZ000-160600-

Mesoscale Precipitation Discussion 0068
NWS Weather Prediction Center College Park MD
1008 PM EDT Sat Mar 15 2025

Areas affected...east-central Alabama into
west-central/northwestern Georgia

Concerning...Heavy rainfall...Flash flooding possible

Valid 160207Z - 160600Z

Summary...A cluster of intense convection was producing areas of
1-2.5 inch/hr rain rates just south of the Birmingham Metro area.
Some concern exists that this activity could persist eastward,
eventually reaching the Atlanta Metro area through 04Z/midnight
EDT.

Discussion...Deep, intense convection has materialized throughout
a strongly sheared, unstable warm sector across
central/southwestern Alabama today. More recently, a cluster of
strong storms (including LEWPs/bows and trailing/training
convection) has produced a localized area of 1-2.5 inch/hr rain
rates just south of Birmingham over the past 1-2 hours. These
rates were approaching FFG thresholds (generally in the 2-inch/hr
range), and areas of at least minor excessive runoff are apparent
given MRMS Flash responses across the region.

Some concern exists that this complex will persist northeastward,
likely crossing the AL/GA border region by 03Z and reaching
portions of the Atlanta Metro area through/after 04Z. The extent
of the flash flood threat may be mitigated by weaker downstream
instability (upper 50s F surface dewpoints contributing to only
around 500 J/kg MUCAPE), which could weaken updraft intensity.=20
However, current convective organization and strong shear should
maintain heavier downpours downstream into northwestern Georgia
and result in at least a few areas of 1 inch/hr rainfall rates -
potentially affecting populated areas such as Atlanta Metro.=20
Given the scenario, at least an isolated flash flood threat should
evolve with this convective cluster through 06Z.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6PkgW2rrRmHcCDSXjUmR1bBndN5Ha0sfrL1oFVZ-5d3mQFMLQT_odohRJTK106XMbTuo= ega-CxuyvNF2pZP_4Qx8dwg$ for graphic product...

ATTN...WFO...BMX...FFC...HUN...

ATTN...RFC...LMRFC...SERFC...NWC...

LAT...LON 34518516 34418416 33868353 33298349 32998378=20
32578531 32368759 33128757 34098620=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 160326
FFGMPD
VAZ000-TNZ000-KYZ000-160925-

Mesoscale Precipitation Discussion 0069
NWS Weather Prediction Center College Park MD
1125 PM EDT Sat Mar 15 2025

Areas affected...middle/eastern Tennessee into central Kentucky

Concerning...Heavy rainfall...Flash flooding likely

Valid 160325Z - 160925Z

Summary...Flash flood potential continues across large portions of
Tennessee and Kentucky. This risk should gradually end from west
to east as a surface trough migrates eastward across the area
through 09Z.

Discussion...Widespread heavy rainfall for much of the day has wet
soils and caused many reports of flash flooding today especially
across Middle Tennessee. 2-7 inch storm total amounts have
fallen, and flash flood guidance depicts widespread areas of
near-zero hourly thresholds from far northwestern Alabama through
north-central Kentucky at the latest update. Meanwhile,
widespread rainfall continues to occur. Most of the rainfall is
light in nature and related to a strong convective MCS centered
over Alabama. A narrow corridor of stronger convection has
redeveloped from near Nashville to Huntsville, however, that
contains areas of 1 inch/hr rain rates at times. This corridor of
stronger convection likely represents the end of the heavy
rainfall threat as it shift eastward across the discussion area
through the early overnight hours as only lighter/isolated shower
activity is noted to its west.

Between now and 09Z, another 0.5-1 inch of rainfall can be
expected areawide (with locally higher amounts). These rainfall
totals will exacerbate ongoing flooding and perhaps lead to
additional runoff problems in sensitive areas.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9dN27J2wElsZ0LJKjflZPrbFzsvJ7zDOs7MCr5Bq9ZmTYbn3GXJVizrxZ1i4jQ9mXhbk= 48RZ5tme3tJFwH3cbpWvU2o$ for graphic product...

ATTN...WFO...HUN...ILN...JKL...LMK...MRX...OHX...

ATTN...RFC...LMRFC...OHRFC...SERFC...NWC...

LAT...LON 38698453 38528347 37578314 36048367 35078458=20
35028645 35758673 36858638 38318563=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 160541
FFGMPD
GAZ000-ALZ000-160840-

Mesoscale Precipitation Discussion 0070
NWS Weather Prediction Center College Park MD
140 AM EDT Sun Mar 16 2025

Areas affected...a small part of southeastern Alabama and
southwestern Georgia

Concerning...Heavy rainfall...Flash flooding possible

Valid 160540Z - 160840Z

Summary...Localized training of storms on the southwestern flank
of a linear MCS near Columbus could pose a localized flash flood
risk over the next couple hours.

Discussion...Scattered to numerous thunderstorms have grown
upscale into an extensive linear segment from near La Grange to
Columbus, GA over the past couple hours. On the southwestern
flank of this MCS, scattered convection continues to increase in
coverage and intensity generally in the area of Troy and
Andalusia, AL. These storms are in a very strongly sheared, moist
and unstable environment with minimal capping. Additionally,
surface wind vectors suggest strong, focused convergence along the
southwestern end of the linear MCS that, when combined with nearly
2 inch PW values, should support areas of training/backbuilding
especially within the stronger instability across southeastern
Alabama. Areas of 2-2.5 inch/hr rain rates have been estimated on
the southwestern flank of the MCS (southwest of Columbus), and
short term trends suggest that heavy rainfall should continue in
this area for at least another couple hours until a surface trough
(extending along I-65 from Montgomery to Evergreen) translates
eastward through the area later tonight.

The mesoscale pattern could support an instance or two of flash
flooding as rainfall totals approach FFG thresholds (generally in
the 2.5 inch/hr and 3 inch/3-hr range) over the next couple hours.
An additional 2-3 inches of rainfall cannot be ruled out in the
wake of the initial MCS. Weaker surface-based instability over
Georgia should mitigate the eastward extent of the flash flood
risk.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6mEZyfPIG80kwjuD4vnYA886Ysn63JTQ9nX8dTa7J3dXElvIf8YGal2xt3OqGplQ3jY2= WWrRlmJ6H3RHHhq8mQB9Jro$ for graphic product...

ATTN...WFO...BMX...FFC...MOB...TAE...

ATTN...RFC...SERFC...NWC...

LAT...LON 32408483 31968419 31168462 31188599 31418651=20
32288564=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 160850
FFGMPD
CAZ000-ORZ000-162049-

Mesoscale Precipitation Discussion 0071
NWS Weather Prediction Center College Park MD
450 AM EDT Sun Mar 16 2025

Areas affected...portions of western and southwestern Oregon

Concerning...Heavy rainfall

Valid 160849Z - 162049Z

Summary...Persistent rainfall is expected to continue to pose a
risk for flooding and localized flash flooding. Another 2-5
inches of rainfall are possible through at least 21Z today.

Discussion...The ongoing regime supporting heavy rainfall
continues, and very little has changed over the past 12 hours.=20
60-70 knot low to mid-level flow remains oriented perpendicular to
the Oregon Coast and Cascades, promoting orographic lift and
continued rainfall amid 500-750 kg/m/s integrated water vapor
transport values. 0.1-0.3 inch hourly rain rates have persisted,
resulting in 1-3.5 inch rainfall totals over the past 24 hours -
highest across southwestern Oregon coastal ranges. This regime
will continue to persist most of the day, with only a slow
southward shift in the low/mid-level jet axes and attendant
precipitation maxima. Another 2-5 inches of rainfall are expected
areawide - with highest rainfall totals expected across
southwestern Oregon (coastal ranges in particular). This
long-duration rainfall event will result in a gradual increase in
flood potential. Streamflows across the region are already above
average, further supporting the idea of enhanced/efficient runoff
with additional rainfall as the day progresses.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9_R1rtv4cWvOsKkuAhgMCqYmvk2VRaKACoS8WhomDFPAYR4Sy_h44tfRCTUx2DXzNCOT= 43UXf_z6Jag2VRPzox0q970$ for graphic product...

ATTN...WFO...EKA...MFR...PDT...PQR...

ATTN...RFC...CNRFC...NWRFC...NWC...

LAT...LON 44892238 44782181 44212150 43242174 42422193=20
41972324 42032432 42822462 43952437 44222390=20
44522317=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 161254
FFGMPD
SCZ000-GAZ000-161552-

Mesoscale Precipitation Discussion 0072
NWS Weather Prediction Center College Park MD
853 AM EDT Sun Mar 16 2025

Areas affected...portions of far southeast GA and SC

Concerning...Heavy rainfall...Flash flooding possible

Valid 161252Z - 161552Z

Summary...A training band of heavy rain is expected to continue to
lead to hourly totals to 3" with storm totals to 5". This could
lead to flash flooding.

Discussion...A bow echo along a convective line in central SC
combined with another mesocyclone near Millen GA have held up
convection across portions of southeast GA and SC. Hourly rain
totals to 3" and local amounts of 5" have been indicated by radar
imagery within this band. Precipitable water values of
1.50-1.75", MU CAPE of 500-1000 J/kg, effective bulk shear near 50
kts, and fairly unidrectional flow with height have fostered the
development of this band.

The 06z HREF guidance suggests that this band should persist for
no more than a few hours. For QPF volume, the 00z ARW appears to
have captured this best, though it's too far northeast with the
footprint. The mesocyclone near Millen GA should force forward
propagation of the band later this morning. Until then, expect
the threat of hourly rain totals to 3" with local amounts to 5"
being possible across portions of extreme southeast GA and SC.

Roth

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!71azd5URerDFRbC3ND0wAvIdIG0g7GkqDj-d3LTDbGgep7Jd6SHNokwY_JH284ueH-xI= 17KwPtUI_oPWzddtfm5psXg$ for graphic product...

ATTN...WFO...CAE...CHS...FFC...

ATTN...RFC...SERFC...NWC...

LAT...LON 33988040 33308001 32918085 32728216 33318182=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 162043
FFGMPD
CAZ000-ORZ000-170730-

Mesoscale Precipitation Discussion 0073
NWS Weather Prediction Center College Park MD
442 PM EDT Sun Mar 16 2025

Areas affected...Southwest Oregon...Northern California...

Concerning...Heavy rainfall

Valid 162045Z - 170730Z

SUMMARY...Flooding risk reducing as cyclone makes landfall and
warm conveyor belt presses quickly southward to intersect coastal
range and northern Sierra Nevada Foothills with heavy rainfall.

DISCUSSION...Southwest Oregon has been experiencing prolonged
moderate rainfall for over 24hrs at this point with large areas of
4"+ totals across much of the area of Coos, Douglas, Josephine and
northern Jackson counties and spots in the boreal rain forests of
Curry county in the 8-10" ranges. Longer duration flooding has
been going in atypical locations with the prolonged heavy
rainfall. The strong onshore moisture flux will be ending in the
next hour or so, but a strong surface wave can be seen with a
secondary one further west along an old occluded front. Steeper
lapse rates due to CAA aloft and some modest retention of moisture
along the boundary may allow for some scattered shower activity to
cross SW OR along the occluded front into the stationary front
that crosses into central OR. Rates up to .25-.33"/hr are
possible but will be more scattered in nature and may result in
those ranges of totals in a sub-hourly manner. This is not likely
to further contribute to enhanced flooding, but will slow its
ending for a few more hours.=20=20

Further south...GOES-W Visible imagery shows the cold front and
more directed atmospheric river/warm conveyor belt has started a
southward progression. The core of .75-.9" total PWat continues
to be advected from strong 40-50kt 850mb winds allowing for IVT
values to remain at 650-700 kg/m/s near the triple point that is
near the OR/CA coastline and southeastward. Upper-level
height-falls will continue to support increasing south and
eastward propagation of the cold front and therefore
onshore/upslope moisture flux. Occasional rates of .33-.5"/hr are
possible especially along the steepest inclines of the northern
Sierra Nevada foothills, but duration of moderate rainfall is
likely to be limited to a few hours and likely only result in
spotty totals of 1.5-3" in traditional locations in Butte, Tamaha
and Yuba counties. Coastal Ranges are more likely to see
1.5-2.5", reducing to .75-1.5" by the time the plume further
weakens (wind speeds down to below 35kts) and IVT values fall
below 400 kg/m/s...nearing the mouth of San Francisco Bay between
03-06z. A secondary weaker band of scattered showers will wrap
around the surface low as it translates east and affects the NW
California after 00z as well, adding another .5-.75" for the
totals. Bringing the overall event to close in the early morning
hours tonight.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5nnx9kBXfO4owThSuTG3TcFLcpoLPpnuE59scDkR7fjNIfb7IZmLoD24j9WynYUVfjKv= xqr-e-TbeJ15Le6vVwyrdY8$ for graphic product...

ATTN...WFO...EKA...MFR...MTR...STO...

ATTN...RFC...CNRFC...NWRFC...NWC...

LAT...LON 43762376 43402333 42922284 42092262 41122202=20
39922140 39382078 38672050 38392087 38572132=20
39852189 40562243 39762260 38632211 38022277=20
38442338 39022398 39812419 40592462 41122434=20
41812430 42392466 42882466 43412443 43742423=20 =20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 162158
FFGMPD
VAZ000-NCZ000-170400-

Mesoscale Precipitation Discussion 0074
NWS Weather Prediction Center College Park MD
558 PM EDT Sun Mar 16 2025

Areas affected...Northeast NC...Southeast VA

Concerning...Heavy rainfall...Flash flooding possible

Valid 162200Z - 170400Z

SUMMARY...Continuation of stronger cells capable of 1.5-2"/hr
rates with upstream redevelopment probable resulting in possible
streets of 3"+ totals and localized flash flooding conditions.

DISCUSSION...RADAR mosaic depicts a cluster of stronger elongated
updrafts in proximity to the I-95 corridor tracking through an
area that had already seen an earlier round wetting the grounds
with spots of .75-1.5" as far north as Petersburg/Wakefield, VA.
These cells are aided by a divergence maxima rounding the cyclonic
edge of a fairly laminar upper-level jet. This pattern is
expected to remain similar with a very slow eastward progression;
as such, 500-1000 thickness ridge resides along/just east of the
I-95 corridor and with solid 45-50kts of moist 850mb flow, there
is ample potential for additional upstream redevelopment.=20=20
Alignment of the moisture axis and instability axis appears to be
fairly stable in placement as well with upstream well of 1000-1500
J/kg of MLCAPE to the west and 1.5 to 1.75" of total PWats
eastward. Solid deep layer confluence is providing the upstream
convergence to allow for back-building/redevelopment. However,
the updraft strength is offset a bit being on the gradient of the
instability axis, resulting in inconsistent, narrow updrafts but
stronger cloud base moisture flux allows for efficient loading to
support 1.5-2"/hr rates. Lengths of the updrafts should allow for
an hour or so of training for streaks of 1.5" with each
pulse/round of convection moving northward.

Stronger convergence along the cold front as the base of the trof
drifts eastward is likely to occur after sunset and likely spell=20
the last round, this may be after 04z (the end valid time of this
message) and trends will need to be continually monitored for
additional training and longer duration totals of 3-4" when all is
over earlier tomorrow morning. Area has been fairly dry and FFG
values are high (especially further east in the Coastal Plain);
however, given each round slowly infiltrated and saturates the
upper soils reducing it for the next round. While, an incident or
two of flash flooding is possible, it is more likely to be
isolated, lower-end with greatest risk of higher magnitude of
flooding in urban locations such as Raleigh, Rocky Mount, Emporia,
Petersburg and the Hampton Roads vicinity of SE VA.=20=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5iY5coMLNs81Tr5eQT0UFxE04VIqjH8-mHIs9W4KB6MNGOWjJEA0ZHVJVXa-ktQ6kJzE= XvY4ZQOIjalgGcDRcMqw_Sc$ for graphic product...

ATTN...WFO...AKQ...MHX...RAH...

ATTN...RFC...MARFC...SERFC...NWC...

LAT...LON 37897661 37867619 37297617 36797596 36597603=20
36207647 35347760 35007846 35417909 36347852=20
37367736=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 162247
FFGMPD
NCZ000-SCZ000-GAZ000-170400-

Mesoscale Precipitation Discussion 0075
NWS Weather Prediction Center College Park MD
647 PM EDT Sun Mar 16 2025

Areas affected...Central SC...South-central NC...

Concerning...Heavy rainfall...Flash flooding possible

Valid 162245Z - 170400Z

SUMMARY...Expanding thunderstorms within favorable repeat/training
environment pose possible isolated incidents of localized flash
flooding into early overnight period.

DISCUSSION...Regional RADAR and GOES-E VIS/EIR loops show
destabilization and convective growth across the Piedmont of
central SC starting to move into central NC. Clear skies
throughout the day allowed for increased insolation and temps to
rise into the upper 70s, low 80s along a tight deep layer moisture
gradient. However, surface low level confluence with
southwesterly flow intersecting with SSW 10-15kts of flow backed a
bit off the coastal Plain is providing sufficient moisture
convergence given Tds into the low to mid 60s. That flux and
solid updraft strength is supporting 1.5"/hr rates. Deep layer
steering does support fast cell motions, however, it is fairly
ideally aligned with the low-level convergence axis to allow for repeating/training, though slow eastward propagation is expected,
spots of 2-2.5" totals in 1-2 hours which is close to exceeding
the FFG values mainly along the Fall-line and the axis of
saturated soils from this morning's heavy rainfall from Allendale
county to Orangeburg county to N Dillon county where 1hr FFG
values are 1.5-2" and 3hr are 1.5-2.5".=20

There is some uncertainty in potential for favorable back-building
environment especially toward the GA/SC line. Stronger forcing
near the southeast base of the rounded upper-level (500 to 300 mb)
jet should support divergence aloft and weak DPVA to aid low level
inflow for back-building; however, drier air infiltrating aloft
also looks to be mixing downward and overall Pwats are decreasing
upstream suggestive of drier air mixing and increasing eastward
propagation limiting training/repeating potential.=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6dVV0h7LxCbuKBuOcrFbI-UdTFgw93lAczQB7HCq95kV_2qK-BA_XAcPQduZYi1jHgo0= phmMPnTxOpmwQefHRxLyLtM$ for graphic product...

ATTN...WFO...CAE...CHS...GSP...ILM...RAH...

ATTN...RFC...SERFC...NWC...

LAT...LON 35777959 35627911 35257877 34747884 34347905=20
33907955 33158060 32738168 33088194 34098138=20
34578106 35518014=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 170225
FFGMPD
NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-170824-

Mesoscale Precipitation Discussion 0076
NWS Weather Prediction Center College Park MD
1024 PM EDT Sun Mar 16 2025

Areas affected...portions of the Mid-Atlantic

Concerning...Heavy rainfall...Flash flooding possible

Valid 170224Z - 170824Z

Summary...Gradually deepening convection will migrate
northeastward across the discussion area for the next several
hours. Rates of 1-2 inches/hr are expected - highest across
eastern Maryland into the DelMarVa. Isolated flash flooding is
possible in this regime.

Discussion...Several atmospheric factors are combining to result
in increasing convective coverage and heavy rainfall across the
discussion area, including: 1) convergence along a surface cold
front extending from Charlottesville, VA to near Lancaster, PA, 2)
strong low-level flow/warm advection, which was maintaining deeper
convection near/east of Richmond, VA while also maintaining ~500
J/kg SBCAPE and 1-1.5 inch PW ahead of the front, 3) advancing
mid/upper level vorticity (and ascent) from troughing centered
over the Ohio Valley and central Appalachians.

As these features continue to evolve slowly eastward over the next
few hours, axes of heavier rainfall will continue to spread
east/northeastward along and ahead of the aforementioned cold
front. Spots of 1 inch/hr rain rates can be expected at times
nearer the front, while heavier rainfall (including 2-2.5 inch/hr
rain rates) could occur out ahead of the front as is currently
being estimated near/east of Richmond, VA. FFGs across the
discussion area are lowest across the DC-to-Philadelphia I-95
corridor (0.5-1.0 inch/hr) and these thresholds could be eclipsed
on an isolated basis over the next 2-4 hours as the front makes
its way eastward through the region. Heavier rain rates are
expected east of I-95 toward the DelMarVa, although it appears
that ground conditions/FFGs are a bit less sensitive in these
areas, suggestive of more isolated flash flood potential. 2-3
inch rainfall totals are expected across the DelMarVa through 08Z
tonight, with lighter totals expected elsewhere.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7Ce5av1YTI927ZG7X7fk5468shHGtUbotqmqvLvoedAIbDL3bVJ0yI5ANf6KErC3x2Ph= W1OxS8Q4GPh1UU3jnDhLs7E$ for graphic product...

ATTN...WFO...AKQ...CTP...LWX...PHI...RNK...

ATTN...RFC...MARFC...NWC...

LAT...LON 40787539 40437427 39587434 38027549 37357691=20
37677889 38807814 40237663=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 170445
FFGMPD
VAZ000-NCZ000-170900-

Mesoscale Precipitation Discussion 0077
NWS Weather Prediction Center College Park MD
1244 AM EDT Mon Mar 17 2025

Areas affected...northeastern North Carolina into southeastern
Virginia

Concerning...Heavy rainfall...Flash flooding likely

Valid 170444Z - 170900Z

Summary...Deep convection continues to develop across North
Carolina and stream north-northeastward into southeastern
Virginia. 1-2 inch/hr rain rates persist in the strongest
activity. This regime should continue for at least another 3-4
hours, posing a continued risk of flash flooding.

Discussion...Convection has continued to refire along a surface
trough extending from just east of Richmond, VA to just east of
Raleigh, NC over the past couple hours. This trough has allowed
for convective development to remain oriented generally parallel
to deep south-southwesterly flow aloft, allowing for substantial
training in a few locales. Additionally, 1.5+ inch PW values and
500 J/kg SBCAPE supports efficient rainfall processes with the
ongoing storms. Ascent from upstream mid-level troughing
continues to result in ascent/height falls over the trough as
well. These factors support continued, SSW-NNE oriented training
bands of storms for the next 2-4 hours or so.

Over time, eastward translation of the surface trough and
mid-upper forcing will lead to an eventual end of heavy rainfall
potential - most likely after 08-09Z. Between now and then,
concern exists that these training convective bands could
eventually make it in to populated, sensitive areas of
southeastern Virginia where lower FFGs (around 1 inch/hr) could
result in a few areas of flash flooding. It is not out of the
question for rain rates to double those lower values (generally
extending from near Richmond southeastward through Virginia Beach)
and lead to locally significant impacts.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8Y2go9nfNkgnIXmUE6p5CsTdp6lYfOFWqV83E671QGmN4vdHIn9_sfKnoBF5s5mDutI1= rQSOJlbJj7BPykGub9s1shI$ for graphic product...

ATTN...WFO...AKQ...MHX...RAH...

ATTN...RFC...MARFC...SERFC...NWC...

LAT...LON 37587690 37067613 36627606 36017677 35477799=20
36767811 37557755=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 231427
FFGMPD
WAZ000-240230-

Mesoscale Precipitation Discussion 0078
NWS Weather Prediction Center College Park MD
1026 AM EDT Sun Mar 23 2025

Areas affected...Northwest Washington....

Concerning...Heavy rainfall

Valid 231430Z - 240230Z

SUMMARY...Prolonged onshore moisture flux across Olympics and
lower Foothills of northern WA Cascades may result in spots of
3-5" totals, given over .33"/hr average rates. Saturated grounds
and some snow melt may increase run-off increasing stream flows.

DISCUSSION...GOES-W WV suite depicts a strong upper-level jet
across the northeast Pacific/southern Gulf of Alaska crossing
central BC before extending southeast into the southern Canadian
Rockies resulting in solid ridging across the Pacific Northwest
with apex of the ridge just west of the coast. This allows for
moderate divergence aloft across southwest BC/northern WA which is
expected to persist through much of the day today allowing for
solid westerly onshore, ascending flow into this divergent area.=20
The southern edge of a warm front has reached the NW WA coast and
is aiding in the ascent/WAA which has started to increase over the
last hour or so across the Olympics. Additionally, this leading
pulse has brought increased low to mid-level moisture via a very
broad atmospheric river plume with sfc-850mb LPW values in the
.5-.6" range with a dual core 850-700mb flow of .25-.3", though
the northern plume/fetch is longer more directed toward southern
Vancouver Island and the NW tip of WA. As a result, 1-1.2" total
PWats are expected being fluxed with 35kts increasing to 50+kts
toward 18-21z. Overall IVT values will increase from 400-450
kg/m/s currently peaking at 650-700 kg/m/s toward 21-00z...then
leveling out around 500 kg/m/s for the rest of the evening into
the overnight.=20=20

The plume's orientation will remain steady through this surge of
moisture flux and favorably intersect the Olympic range with rates
of .15"/hr currently to increase to near/just over .5"/hr in the
best orographic ascent by 18z. The core of the flux will be
north into southern Vancouver Island, but will then slide toward
the northern WA Cascades through the late afternoon/early evening
increasing rates of .25-.33", perhaps occasionally reaching .5"/hr
at the peaks. The depth of warm air will result in freezing
levels lifting above all but the highest peaks. This has a
combination of those high rates but also rain upon snow.=20
Temperatures are not going to be significantly over freezing, so
melt may be a bit slow, but will contribute to run-off. Soil
saturation values are very high (or even 100% due to snow pack),
so much of the water from rainfall will run-off too increasing
potential for above average stream flow but not likely to rise
fast enough for rapid-rise/flash flooding.=20=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7u5LhiU2H0T2GdeZ8a0qufxxSFrwQchurSmg0fp_8FpNZ0CDyOeeFItU1Ry6XEvV_GMI= UmW2gV4K632D0NIAFMNNgdA$ for graphic product...

ATTN...WFO...SEW...

ATTN...RFC...NWRFC...NWC...

LAT...LON 49132248 49112172 48982125 48322116 47602148=20
47452178 48022208 48152248 48042298 47812312=20
47472321 47272338 47212383 47322417 47592451=20
47942466 48362485 48432447 48222370 48432313=20
48772304 49092285=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 232206
FFGMPD
TNZ000-ALZ000-MSZ000-ARZ000-240400-

Mesoscale Precipitation Discussion 0079
NWS Weather Prediction Center College Park MD
605 PM EDT Sun Mar 23 2025

Areas affected...Western & Middle TN...Northern MS...Northwest
AL...

Concerning...Heavy rainfall...Flash flooding possible

Valid 232205Z - 240400Z

SUMMARY...Multiple rounds of intense showers/thunderstorms with
rates of 1-1.5"/hr may allow for a few streets of repeating cells
and 2-3" localized totals nearing/exceeding FFG values resulting
in possible widely scattered incidents of low-end flash flooding,
particularly near urban centers.

DISCUSSION...GOES-E WV suite depicts a strong, compact short-wave
across N IL/S WI moving quickly east with a lower-scale
wave/mid-level trough accelerating eastward into the upper-Ohio
River Valley. This is accompanied by a strong upper-level jet
streak that has rounded the base of the main trof with solid right
entrance ageostrophic response across the lower Ohio Valley
providing strong divergence along and south into the Tennessee
River Valley.=20

Surface and LLJ has responded with increasing Southwesterly flow
fluxing higher theta-E air northward with Tds into the upper 50s
and lower 60s. Filtered insolation and mid-level steepening lapse
rates have made the area modestly unstable with MLCAPE nosing
across W KY into W TN over 1000-1250 J/kg, along and ahead of
solid cold front. Additionally, GOES-E Vis and sfc to boundary
layer streamlines suggest a confluence axis between deeper Gulf
moisture from the Western Gulf and return from the central/eastern
Gulf becoming increasingly confluent across central MS to NE MS
into Middle TN. With conditionally unstable air, this has been
sufficient to break out weaker but slowly increasing convective
activity across Middle TN... with some convection/flux convergence
supporting rates of .5-.75", which is expected to increase over
the next few hours. Forward propagation is likely to limit
overall totals with any individual cell, but could be stage
setting for later development.

As the line expands, cells will have capability for
back-building/flanking line development that is probable to align
with strong/fast steering flow resulting in some accidental
training. However, further upstream cold front is starting to
advance with solid 90 degree convergence along the leading edge
southwesterly LLJ/moisture plume. Cells will expand in coverage
and width and should be capable of 1-1.5"/hr rates as they
advance, with similar very fast (40+ kt) forward speed, likely
limiting overall rainfall totals. Hence, any flash flooding
potential will require these cells to traverse areas already
affected by 1-2" totals with earlier rounds. If so, 2-4hr spot
totals of 2-3" are possible. This is in range of the lower FFG
values over the TN valley (1.5-2"/hr & 2-3"/3hr). As such, a few
widely scattered instances of flash flooding are considered
possible particularly after 00z and in/near urban settings.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5qS4wqKO0XRxof-tpw08nyp5JjttqzzEKkAI-JFPw30tXIEzHdpdsUsi4_LyUGI1LFvE= ooBcRUDKd0DxmmOzIwDWIKM$ for graphic product...

ATTN...WFO...BMX...HUN...MEG...OHX...

ATTN...RFC...LMRFC...OHRFC...SERFC...NWC...

LAT...LON 36488810 36478551 35158602 34288698 33908848=20
34009006 34279071 34979061 35638953=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 232256
FFGMPD
MSZ000-LAZ000-ARZ000-240430-

Mesoscale Precipitation Discussion 0080
NWS Weather Prediction Center College Park MD
656 PM EDT Sun Mar 23 2025

Areas affected...Northern LA...Southern AR...Central MS...

Concerning...Heavy rainfall...Flash flooding possible

Valid 232300Z - 240430Z

SUMMARY...Strong moisture flux convergence with initial convective
development will allow for very quick moisture loading and strong
downdrafts capable of quick 2"/hr rates (15-minute totals of
1-1.5" psbl). As cold front moves east, interaction with older
warm sector convection may allow for localized repeating/training
and spot totals of 2-3" in 1-2hrs resulting in possible flash
flooding.

DISCUSSION...GOES-E Visible/10.3um and RADAR mosaic denote
scattered destabilization occurring across the warm sector mainly
along the Lower Mississippi River Valley at the intersection of
the nose of instability axis (2500-3000 J/kg) of MLCAPE that
extends from the Heart of Texas into northeast LA and the nose of
the deepest sfc to 850mb moisture core (LPW of .8-.9") across
south-central LA into northeast LA. This boundary layer moisture
is quickly advancing northward toward a southward pressing/well
defined (steep isentropes) that is bisecting AR from NE to SW.=20
These cells are expected to be slower moving but with steering
more northward toward the frontal zone before effective bulk shear
increases due to stronger flow aloft across the Delta Region into
the Bootheel of MO. The collision of the air masses is likely to
result in rapid convective development along the front from NW MS
across S AR into N LA and eastern TX mainly in the 01-02z time
frame. There has been solid signal throughout the day toward this
time frame, but trend in the HRRR is a bit earlier and more
focused resulting in very strong moisture flux loading to the
line. Stronger mid-level dry air will likely aid stronger
downdrafts due to mixing but given loading is expected to have
heavy rainfall totals in quick sub-hourly amounts.=20=20

Experimental HRRR 15-min estimates 1-1.25" at onset around 0130z
become near 1.75" by 02-03z across N LA. Hourly totals of 2-2.5"
seem plausible given weaker overall steering before cold
front/outflow boundaries begin to organize and advance eastward.=20
While soil moisture is about 45-55% (in all but the braided
portions of the MS River...65+% there), this is running in the
10-15th percentile, suggesting upper-soils may initially not allow
much infiltration). Still, the spotty/smaller areal coverage may
limit the overall magnitude of flash flooding suggesting highly focused/localized at least initially across S AR/N LA for spotty
possible flash flooding. It is only later toward 04-06z with
some organization and potential west to east training that
localized totals may reach 2-4" through 06z. 18z HREF and recent
HRRR runs support the best probability to be in proximity to the
AR/LA/MS intersection and points east-northeastward. Confidence
is increasing toward possible scattered incidents of flash
flooding through this time period before cells become too
scattered/progressive generally after 06z, but will continue to
monitor trends closely.

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7hIGogkyekcaPFZ5mQuNuFDncu-1T3xDaKXSDtqWIBkgl9Xr33WqK0aQHxJBgQFIzTQH= TN2pU1KMFLkxjA2r89twVmg$ for graphic product...

ATTN...WFO...JAN...LZK...MEG...SHV...

ATTN...RFC...LMRFC...SERFC...WGRFC...NWC...

LAT...LON 34389006 34318925 34248863 33868836 33378837=20
32958857 32398922 32039070 31829179 31709325=20
31989383 32779367 33569269 34099146=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 240421
FFGMPD
ALZ000-MSZ000-LAZ000-241020-

Mesoscale Precipitation Discussion 0081
NWS Weather Prediction Center College Park MD
1221 AM EDT Mon Mar 24 2025

Areas affected...northern LA into central MS and western AL

Concerning...Heavy rainfall...Flash flooding possible

Valid 240420Z - 241020Z

Summary...Periods of training thunderstorms may produce areas of
isolated to widely scattered flash flooding through 10Z across
portions of northern LA, central MS and western AL. Peak rainfall
rates between 1-3 in/hr and spotty totals of 2-4 inches are
expected through 10Z.

Discussion...04Z regional radar imagery showed a WSW to ENE line
of thunderstorms that extended from northern LA into northern AL.
This line formed earlier within an axis of pre-frontal confluence
and has since become the dominant area of convection across the
Lower Mississippi Valley. Farther north, closer to the cold front
itself, were a few scattered thunderstorms, mainly located in TN.
04Z SPC mesoanalysis data showed the environment from northwestern
AL to northern LA contained 500 to 1500+ J/kg MLCAPE (highest to
the west over northern LA) and 1.2 to 1.5 inches of PWAT.

Expectations are for the line of storms to continue advancing
southeastward, ahead of the cold front and along the leading edge
of rain-cooled outflow which has since formed behind the advancing
line. While storm motion should remain progressive and not pose a
significant threat for flash flooding, the environment is, and
will continue to be, capable of producing 0.5 to 1.0 inches of
rain in 15 minutes given forecasts of lingering instability over
the next several hours. Where convective orientation matches the
mean steering flow from the WSW, training will produce 1-2 in/hr
rates, perhaps exceeding 2 inches in an hour. The result will be
spotty 2-4 inches of additional rainfall through 10Z, although the
higher end of that scale is considered a much lower probability of
occurrence. Given relatively high flash flood guidance values
(especially over southern portions of the MPD threat area), any
areas of flash flooding that develop will likely be tied to areas
of poor drainage, particularly those of urban nature.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5iNlAJLMPBL0LowdHFEYBBf6NSLZE3NmvkpPJCf1XN80ciwOnFlAfZocorpASxeUuuTZ= 5vLHHIRe69SoHcrcizDE3oM$ for graphic product...

ATTN...WFO...BMX...JAN...MEG...MOB...SHV...

ATTN...RFC...LMRFC...SERFC...NWC...

LAT...LON 33898746 33168677 32388762 31658960 31399127=20
31559306 32459350 32829180=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 241300
FFGMPD
FLZ000-ALZ000-MSZ000-LAZ000-241659-

Mesoscale Precipitation Discussion 0082
NWS Weather Prediction Center College Park MD
900 AM EDT Mon Mar 24 2025

Areas affected...coastal Mississippi, southeastern Louisiana, far
southwestern Alabama

Concerning...Heavy rainfall...Flash flooding possible

Valid 241259Z - 241659Z

Summary...A couple of linear convective complexes are merging and
could pose an isolated flash flood threat over the next 2-3 hours
from New Orleans Metro eastward through Mobile, AL.

Discussion...Radar mosaic imagery depicts a couple of linear
convective complexes across the discussion area: 1) extending
along an east-west axis from near Mobile, AL to just north of
Baton Rouge, LA that was moving slowly southward and 2) a
faster-moving complex approaching an axis from Hammond to Morgan
City, LA. The orientation of these complexes has fostered some
localized training/repeating, with 1-1.5 inch/hr rain rates noted
per MRMS on a spotty/localized basis. These rates are generally
below FFG thresholds, although some concern exists that as the
convective complexes continue to merge, areas of 1+ inch/hr rain
rates could materialize across more urbanized areas of the region
(generally from New Orleans proper to Mobile) and cause
spotty/isolated flash flooding to materialize. This threat
appears to be highest along the Mississippi Gulf Coast over the
next couple hours.

Both of the linear complexes are progressive enough to suggest
that most of this morning's isolated flash flood threat should end
during the 16Z/11am CDT hour.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_sSfTvyit0fsLPPkcLyhhxiqZLlLuSS5ctoiw9pr19Q5N0fWB7y1XZrpyltdpsig9m2E= 5St-nugHTgro9SwwZt9Ep34$ for graphic product...

ATTN...WFO...JAN...LCH...LIX...MOB...

ATTN...RFC...LMRFC...SERFC...NWC...

LAT...LON 31488818 30878748 30398748 29798898 29369018=20
29539131 30369107 31189086 31448943=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 251826
FFGMPD
FLZ000-260025-

Mesoscale Precipitation Discussion 0083
NWS Weather Prediction Center College Park MD
225 PM EDT Tue Mar 25 2025

Areas affected...Southeast FL

Concerning...Heavy rainfall...Flash flooding possible

Valid 251825Z - 260025Z

SUMMARY...Heavy showers and thunderstorms expanding over southeast
FL may result in some urban flash flooding over the next few hours.

DISCUSSION...The latest GOES-E visible satellite imagery in
conjunction dual-pol radar shows the development and expansion of
heavy shower and thunderstorm activity over southeast FL, with an
emphasis on Miami-Dade County. Cooling cloud tops are noted in a
southwest to northeast fashion from over and west of Homestead and
stretching northeast into the Miami metropolitan area.

A combination of a front settling gradually south down the FL
Peninsula coupled with localized seabreeze convergence near the
urban corridor will facilitate additional convective development
this afternoon. A moderately moist and unstable environment is
already in place with MLCAPE values of 1500+ J/kg and PWs of 1.5+
inches. This coupled with 30 to 40+ kts of effective bulk shear
will favor slow-moving and relatively organized convective cells
capable of producing rainfall rates of 1.5 to 2.5 inches/hour.
Some localized storm totals going through early this evening of 3
to 5 inches will be possible.

While FFGs are very high, these rains are expected to impact
portions of the highly urbanized/populated urban corridors from
Homestead northward up to Fort Lauderdale and possible even West
Palm Beach as the activity further expands in coverage. As a
result, a concern for urban flash flooding will exist over the
next several hours.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6fezOdQZdpWSnZPkSSd7WX3xSI_FOMCiYoS75JXtNKoRd0-L7Phtqc4hqKdVD0huC7Z9= 2lNVrYtUewlHRm9qsaj5Hk4$ for graphic product...

ATTN...WFO...MFL...MLB...

ATTN...RFC...SERFC...NWC...

LAT...LON 26988032 26918004 25998000 25398033 25278061=20
25448082 25938057 26498039=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 260430
FFGMPD
ARZ000-TXZ000-OKZ000-261015-

Mesoscale Precipitation Discussion 0084
NWS Weather Prediction Center College Park MD
1229 AM EDT Wed Mar 26 2025

Areas affected...south-central OK into northern TX

Concerning...Heavy rainfall...Flash flooding possible

Valid 260428Z - 261015Z

SUMMARY...Repeating and training of thunderstorms from south
central OK into portions of northern TX may produce localized
flash flooding later tonight. Potential for 2 to 4 inches along
with rainfall rates of 1 to 2 in/hr (locally higher) will exist
through 10Z.

DISCUSSION...A combination of GOES East infrared satellite and
regional radar imagery at 04Z showed widely scattered
thunderstorms from northeast of DAL to south of OKC. Cloud tops
were generally warming over TX but new development was occurring
across south-central OK where low to mid-level moisture transport
was allowing for generally weak instability to build northward
from the Red River, north of a quasi-stationary front analyzed
over northern TX. The new development was occurring at the nose of
a 30-35 kt 850 mb low level jet as sampled by VAD wind data at
KDYX and KFWS, about 10-15 kt stronger than F000 and F001 hour RAP
guidance suggests.

Nocturnal strengthening of the low level jet is expected to
continue through ~06Z with a max axis between SPS and GYI,
supporting the overrunning of the quasi-stationary front. A
relatively small pocket of elevated instability between 500 and
1500 J/kg is forecast by the RAP to be in place from between I-20
and I-40 on either side of I-35 over the next several hours, but
should lower in magnitude toward 12Z.

Thunderstorms are expected to continue to increase in coverage
over south-central OK over the next 1-3 hours, with mean steering
flow aligned roughly parallel to the surface front, repeating
cells along with instances of training are expected. However, any
clustering of thunderstorms may result in more of a southward
propagation of cells into the inflow layer. Sufficient speed shear
exists for some organized thunderstorms and elements of training
heavy rainfall could result in rates of 1-2 in/hr, though earlier
convection near Dallas in southern Collin County was responsible
for ~1 inch of rain in 15 minutes, so 1-2 inches in less than 1
hour will certainly be possible tonight. Dry antecedent conditions
and high flash flood guidance should limit any flash flood
concerns to urban areas or otherwise sensitive, poorly draining
locations. 2-4 inches will be possible on a localized basis
through 10Z.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7yir3J56soxSS-WTlk0RRuhnRmeEBBntW-T8chuI9ezLR2FYrpUV5D0v_OxihHksyxMk= SwLYT73PzJO9zk3vZN3nmsQ$ for graphic product...

ATTN...WFO...FWD...OUN...SHV...TSA...

ATTN...RFC...ABRFC...LMRFC...WGRFC...NWC...

LAT...LON 35359778 34899659 34079496 33429390 32739422=20
32789547 33469733 34739858 35199836=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 261715
FFGMPD
TXZ000-262315-

Mesoscale Precipitation Discussion 0085
NWS Weather Prediction Center College Park MD
115 PM EDT Wed Mar 26 2025

Areas affected...South-Central and Deep South TX

Concerning...Heavy rainfall...Flash flooding possible

Valid 261715Z - 262315Z

SUMMARY...Developing and expanding clusters of heavy showers and
thunderstorms are expected through this afternoon. Very heavy
rainfall rates and locally slow cell-motions will support an
increasing flash flood threat.

DISCUSSION...The midday GOES-E satellite imagery shows a
well-defined mid-level shortwave trough ejecting east across
northwest mainland Mexico which will begin to cross the Rio Grande
Valley by later today. Increasingly divergent flow aloft ahead of
these height falls along with some smaller scale vort energy will
be gradually overspreading the lower Rio Grande Valley and
adjacent areas of south-central TX and will be interacting with an
increasingly moist and unstable airmass.

MLCAPE values over much of the region are already locally on the
order of 1500 to 2000 J/kg, with PWs of 1.5 to 1.75 inches.
Persistent low-level south-southeast flow will continue to bring
moisture up across much of southern TX in general going through
the afternoon hours, and the latest CIRA-ALPW and MIMIC-TPW data
sets show notable concentrations of deeper and more anomalous
moisture advecting into the lower Rio Grande Valley ahead of the
upstream mid-level height falls/shortwave energy.

This will set the stage for developing and expanding clusters of
heavy showers and thunderstorms going through the afternoon hours.
The convective cells in this moistening environment should become
increasingly efficient and will be capable of producing very high
rainfall rates considering the level of instability and some
uptick in updraft helicity parameters.

The 12Z HREF guidance suggests the stronger and more organized
convective cells may be capable of producing 2 to 3 inch/hour
rainfall rates. A combination of multicell and some isolated
supercell structures are generally expected to evolve over time,
and some of the cells that become more deeply rooted are expected
to potentially become very slow-moving with cell-motions a bit to
the right of the deeper layer mean flow. This will support some
locally enhanced rainfall totals, with some rainfall totals by
early this evening of 3 to 5+ inches possible.

Antecedent conditions are very dry, but with such high rainfall
rates and potential for slow cell-motions, the threat for flash
flooding will be increasing with time. Additional MPDs will likely
be required this evening to further address the excessive rainfall
threat going into the overnight hours.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4aPFlnQ_WWQm9hc6kTt-06RSX7IdGQfndG2Vwt8UA4aR2YV7FEW9O1vcMKua9pksn0_Q= EPjdyCFI2HiIQV1Rz1KgAYQ$ for graphic product...

ATTN...WFO...BRO...CRP...EWX...

ATTN...RFC...WGRFC...NWC...

LAT...LON 29289749 28919687 28229668 27529713 27149726=20
26709731 26009720 25929757 26109820 26369895=20
26729931 27479964 27839989 28240022 28800007=20
29279882=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 262319
FFGMPD
TXZ000-270518-

Mesoscale Precipitation Discussion 0086
NWS Weather Prediction Center College Park MD
719 PM EDT Wed Mar 26 2025

Areas affected...portions of south Texas

Concerning...Heavy rainfall...Flash flooding likely

Valid 262318Z - 270518Z

Summary...Areas of heavy rainfall continue to move slowly across
the discussion area, with redevelopment of deep/intense convection
noted along/just west of the Rio Grande recently. Flash flood
potential (locally significant) should continue through 05Z/11p
CDT and likely beyond.

Discussion...Over the past 6 hours, scattered to numerous
thunderstorm activity has produced areas of 1-5 inch rainfall
amounts - highest northwest of Corpus Christi and northwest of
McAllen. Prior dry conditions and high FFGs suggested that these
rainfall totals have likely resulted only minimal impacts so far,
though wetting soils should gradually result in the region
becoming more susceptible to flash flooding as additional rainfall
develops across the region tonight.

Meanwhile, radar/satellite mosaic imagery indicates
redeveloping/strengthening convection along and either side of the
Rio Grande Valley, with additional strengthening storms located
just north of Corpus Christi. Wind fields aloft have strengthened
across the discussion area in tandem with better ascent/lift,
which is the likely culprit for the recent increase in convective
coverage. Increased wind shear has enabled a few of the
convective structures toexhibit right/deviant motion with speeds
as slow as 5-10 knots and rain rates exceeding 2 inches/hr.

Over time, concern exists that convection near the Rio Grande
could grow upscale into one or more convective complexes. These
complexes will move very slowly while continuing to exhibit
embedded rotation and occasional cell mergers that should enhance
rain rates. Localized areas of 3-5 inch rainfall totals are
expected, and significant flash flooding could become a great
concern if higher rain rates were to materialize in
sensitive/urbanized portions of the discussion area.

A secondary concern for upscale growth/backbuilding exists
near/just north of Corpus Christi where low-level confluence
exists on the northern extent of 20-25 kt 850mb flow. A few of
these areas have already experienced 2-5 inch rainfall totals
today. Additional rainfall could result in flash flooding
especially if a more persistent convective band could become
established.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6rl1j1YZhZDJqe53V_RjJH2MXwSfghCpBfsOtGddV2TNxyeRFOEiI-lCNUsmSupXuQq2= kaxU-Zb1wQ7Hr3gbZt1RxVU$ for graphic product...

ATTN...WFO...BRO...CRP...EWX...HGX...SJT...

ATTN...RFC...WGRFC...NWC...

LAT...LON 30599832 30329724 29809654 29259617 28569631=20
27869674 27099719 26499730 26349770 26379853=20
26649920 27329952 28049993 28730053 29050080=20
29620131 30180112 30559991=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 270511
FFGMPD
TXZ000-271100-

Mesoscale Precipitation Discussion 0087
NWS Weather Prediction Center College Park MD
111 AM EDT Thu Mar 27 2025

Areas affected...Deep South Texas...

Concerning...Heavy rainfall...Flash flooding possible

Valid 270515Z - 271100Z

SUMMARY...Highly uncertain convective environment with ample
moisture, persistence of moderate to heavy rainfall may result in
possible localized flash flooding potential through early morning.

DISCUSSION...A very complex dynamic environment remains across
much of southern Texas this evening. An elongated mid-level
trough axis exists generally along 30N with multiple weaker
vorticity rolls ebbing and shearing with influence of changing
lower-level moisture/instability field feeding back through
convective feed-back and latent heat release. WV suite denotes
favorable right entrance ascent pattern with anticyclonic curved
transverse banding features moving downstream into E TX/N LA;
while left exit favorable divergence ascent pattern is expected to
replace and further support indirect thermal circulation and back
low level flow from southeast to easterly to strengthen isentropic
ascent, perhaps triggering additional development as noted west of
Zapata county along the western moisture gradient at 700-500mb and
traced well in the CIRA LPW layers. It can be also noted the new
convection is ascending along the veered sfc to 850mb and then
further 850mb to 700mb from southeast to south-southwest,
respectively. Additionally, RADAR and SWIR loop suggest a weak
MCV from older convection just west of NW Webb county, moving east
may be affording additional strengthening of the southerly turning
of the winds.

Overall, the more southerly flow intersects with the dying
outflow/convective line across south Texas, that has laid out
fairly orthogonal to the strengthening low level flow. Cell
motions will be more northward, though this boundary and the
effective bulk shear in the 35-40kt range is suggestive of greater
cell organization for enhancing low level moisture flux into the broadening/rotating updrafts. Rapid refresh models like the
RAP/HRRR have started a trend toward this convective mode, which
in turn, trends to increased longevity. Overall deep layer
moisture remains solid with .75-1", sfc to 850mb LPW values along
the Lower Rio Grande, over-topped with .4-.6" in 850-700mb, though
hints of some dry air mixing along that western gradient of dry
air pressing eastward may result in some entrainment, but should
also aid in steepening lapse rates for increasing some instability
for deeper/stronger updrafts, though proximity to modest 700-500mb
moisture allows for the total column to remain near or slightly
above 1.75"; higher to the southeast nearer the Gulf source.=20=20
However, there has been some mixing/overturning from the initial
convection to leave the instability field more scattered and
pocketed in nature; likely resulting in some uncertainty on the
persistent vigor of the updrafts. However, there are remains of
1500-2000 J/kg of CAPE mainly south of the River, that should
allow for cells capable of rates over 2"/hr for an hour or so and
scattered within the area of concern.

Cell motions will increase potential for flanking line
development/repeating with a more eastward component for the
stronger/rotating cells and more north-northeastward for weaker
ones. As a result the environment for intersection/repeating is
going into the storm-scale interactions which are notoriously
difficult to assess/forecast and so confidence is not very high in
incidents of flash flooding; especially given the area of best
overlap/signal of heavy rainfall is generally north and across the
rural and naturally higher FFG values of Zapata,Jim Hogg, Brooks,
and Kenedy counties. However, proximity of the boundary further
south may be poorly resolved in the guidance nearer the urban
areas north of the river, and the earlier rainfall in Starr and S
Jim Hogg counties may receive an additional 2-4" locally inducing
flash flooding. All considered, the risk of flash flooding
remains possible through the early morning hours across Deep south
Texas.=20=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4rC0G-FOvh2aQdHX2I-yG6TMcHBTxX2b_Mg8p-FVIsNYVWrN_Jl-BdQzArh3JGCZL1dJ= ROIhuOotL9O3bzRCctJeKlM$ for graphic product...

ATTN...WFO...BRO...

ATTN...RFC...WGRFC...NWC...

LAT...LON 27149894 27059845 26849767 26809716 26069705=20
25809737 25999773 25989800 26169857 26389909=20
26749934 27089943=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 271422
FFGMPD
TXZ000-271900-

Mesoscale Precipitation Discussion 0088
NWS Weather Prediction Center College Park MD
1020 AM EDT Thu Mar 27 2025

Areas affected...Lower Rio Grande Valley

Concerning...Heavy rainfall...Flash flooding possible

Valid 271420Z - 271900Z

SUMMARY...Some expansion of heavy showers and thunderstorms are
expected through this morning and into the early afternoon hours.
Heavy rainfall rates and locally slow cell-motions will foster a
threat for additional flash flooding concerns.

DISCUSSION...A mid-level trough continues to gradually advance
east across the southern High Plains and adjacent areas of
northern mainland Mexico with multiple embedded vort centers seen
in GOES-E IR/WV satellite imagery ejecting out of the base of it
toward the lower Rio Grande Valley.

Radar imagery shows one band of convection that has slowly
progressed through Deep South Texas over the last few hours, with
the core of this activity now situated over far northeast Mexico.
However, there is redevelopment seen farther northwest to the
southeast of Laredo involving Zapata, Jim Hogg, and Starr
Counties. This convection is generally forming along a weak
instability gradient that is also aligned along an inverted
surface trough which is gradually attaining sufficient
baroclinicity to be classified as a weak stationary front.

Despite rather modest instability parameters with MLCAPE values of
500 to 1000 J/kg, there will likely be some gradual recovering of
instability with time across Deep South Texas to the southeast of
this weak frontal zone which will strengthen the overall
instability gradient. This coupled with ejecting vort energy and
the left-exit region of an upper-level jet streak from northern
Mexico across the lower Rio Grande Valley will likely tend to
support and sustain the redeveloping areas of convective activity
with some gradual expansion off to the northeast expected with
time.

PWs are generally in the 1.5 to 1.7 inch range across the area,
and this coupled with the instability should be capable of
favoring convection with 1 to 2 inch/hour rainfall rates going
through the morning and early afternoon hours. The latest hires
CAM guidance is handling the ongoing activity very poorly, so
confidence is generally quite low, but given the latest convective
trends, some additional rainfall totals going through early
afternoon may reach 2 to 4 inches with isolated heavier amounts
not out of the question given slow cell-motions.

Given some of the heavier rainfall from overnight and early this
morning, and thus the moistening up of the soil conditions, these
additional rains over the next several hours may result in some
additional flash flooding concerns.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7yGQbC0BOQX8nuGEbtr0eD5gL0LsuaytCRvB9lG0U3-n6-eCMJWmsg8izXHpTmssRSNH= oPC9bApWRWf4IRsWdzlWu0U$ for graphic product...

ATTN...WFO...BRO...CRP...

ATTN...RFC...WGRFC...NWC...

LAT...LON 27619834 26959776 26359713 25829719 25959804=20
26459909 27159953 27609918=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 271858
FFGMPD
TXZ000-280057-

Mesoscale Precipitation Discussion 0089
NWS Weather Prediction Center College Park MD
257 PM EDT Thu Mar 27 2025

Areas affected...Deep South TX

Concerning...Heavy rainfall...Flash flooding likely

Valid 271857Z - 280057Z

SUMMARY...A strong and well-organized QLCS gradually settling down
through Deep South TX will be capable of producing very heavy
rainfall rates and a general likelihood for flash flooding heading
into the early evening hours.

DISCUSSION...GOES-E IR satellite imagery in conjunction with
dual-pol radar shows a well-defined QLCS gradually settling
eastward down across Deep South TX. This convective complex is
being strongly favored by the ejection of left-exit region
upper-level jet dynamics across the lower Rio Grande Valley
downstream of a deeper layer trough crossing northern Mexico and
parts of the southern High Plains.

This energy is also interacting with a quasi-stationary frontal
zone and the pooling of a modestly unstable airmass characterized
by MLCAPE values of near 1000 J/kg. While instability is rather
modest, there is a rather favorable shear environment for a
continuation of organized convection over Deep South TX with
stronger mid-level winds helping to support as much as 40+ kts of
effective bulk shear. Some additional uptick in diurnal heating
over the next few hours should support some additional boundary
layer destabilization and this coupled with a convergent and moist
low-level south-southeasterly jet of 30 to 40 kts should support
convection with high rainfall rates capable of reaching 2 to 3
inches/hour with the stronger storms. In fact, the latest
CIRA-ALPW data shows a notable surge/wave of higher PWs/moisture
concentrated in the SFC/850 mb layer lifting northwest out of the
Bay of Campeche and taking aim on Deep South TX. Speed convergence
associated with this in conjunction with the implied stronger
moisture transport will further enhance the rainfall rate
potential over the next few hours.

The 12Z HREF guidance along with numerous runs of the HRRR
continue to struggle with the details and evolution of the ongoing
convective activity more regionally over southern TX. Accounting
for the current activity, the HRRR is closest from a convective
mode/object perspective, but is way too slow with its evolution.
Basically the HRRR 00Z to 06Z/Fri QPF signal is likely to occur
more over the next 6-hours based on the latest satellite and radar
trends.

High rainfall rates and rather slow cell-motions with the QLCS
evolution should favor additional rainfall amounts of as much as 3
to 5 inches, and especially where any transient areas of
cell-training can occur. Given the wet antecedent conditions from
earlier heavy rainfall, these additional rains are likely to cause
additional areas of flash flooding heading into the early evening
hours, and this will include the Brownsville vicinity.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9lJw7qhr-YditUF01Jsskdf0F1HyOx-VligRuIWX7GghXyGUKavp5zBbEsD-Qg8grHcs= y4kj0RwOjuo95XTSHkADn00$ for graphic product...

ATTN...WFO...BRO...CRP...

ATTN...RFC...WGRFC...NWC...

LAT...LON 27509751 27429722 26879728 25919702 25739713=20
25959801 26199884 26569899 27159840=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 280038
FFGMPD
TXZ000-280636-

Mesoscale Precipitation Discussion 0090
NWS Weather Prediction Center College Park MD
837 PM EDT Thu Mar 27 2025

Areas affected...south Texas

Concerning...Heavy rainfall...Flash flooding likely

Valid 280036Z - 280636Z

Summary...Locally significant flash flood potential should
continue through 06Z/1am CDT.

Discussion...A very slow-moving cluster of deep, intense
convection continues to make progress across Deep South Texas
while producing multiple hours of 1-3 inch/hr rain rates. These
rates have falling in populated areas near McAllen and Harlingen,
prompting significant impacts.=20

Radar mosaic imagery indicates the leading edge of a cold pool
extending from just north of Brownsville west-southwestward along
and just south of the Rio Grande River. Meanwhile, mesoanalyses
and satellite imagery indicate renewed convective development
across portions of northeastern Mexico associated with a mid-level
shortwave trough centered near 27.3N, 101.4W. Steep lapse rates
aloft were located just west of the ongoing complex and much of
northern Mexico as well.

While the heavy to extreme rain rates currently being observed
just north of Brownsville may shift offshore over the next couple
hours, the combination of a trailing/lingering outflow boundary
near the Rio Grande and upstream ascent/instability from
aforementioned lapse rates should result in a continued threat of
at least elevated convection over the next 3-6 hours. The
heaviest rainfall threat will be modulated by the southward shift
of the outflow boundary - should this boundary drift back to the
north into south Texas, a renewed threat for 2+ inch/hr rain rates
could materialize and raise continued, significant flash flood
potential. At least areas of 1-2 inch/hr rain rates are expected
with deep convection given the upstream instability and lift -
even with elevated convective activity. Ground conditions are
inundated with significant impacts being reported amid near-zero
FFGs from Harlingen westward to Rio Grande City. Additional
rainfall will likely exacerbate those impacts.

Cook

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5p028T9sL6KQXZnanMNZMTqQdWg8mAvmVIXWa_cm3sm3lHjz3ELz06uE-otCSh8jSDmD= 0U54iXplbl5S9GWvSUC6cGI$ for graphic product...

ATTN...WFO...BRO...CRP...

ATTN...RFC...WGRFC...NWC...

LAT...LON 27539856 27469744 26169691 25879768 26469918=20
27129935=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)

AWUS01 KWNH 280457
FFGMPD
TXZ000-281000-

Mesoscale Precipitation Discussion 0091
NWS Weather Prediction Center College Park MD
1256 AM EDT Fri Mar 28 2025

Areas affected...Lower Rio Grande Valley and Lower Texas Gulf
Coast...

Concerning...Heavy rainfall...Flash flooding likely

Valid 280500Z - 281000Z

SUMMARY...Strong MCV, providing ascent for another round of strong thunderstorms capable of 2"+/hr rates to further compound ongoing
significant flash flooding across the Rio Grande Valley. Heavy
rainfall likely to expand northward toward Corpus Christi urban
areas over the next few hours as well, with possible flash flooding

DISCUSSION...GOES-E WV shows strong vorticity center/MCV currently
along the south-southwest side of the larger scale stationary
upper-level low crossing over the Rio Grande into Webb county.=20
These height-falls have once again backed the low level flow off
the very moist/unstable western Gulf that had filtered across
Tamaulipas and into eastern Nuevo Leon state in Mexico. CIRA LPW
shows surface to boundary layer moisture nearing 1" fluxed on
30-35kts toward the flanking line, allowing for increased
instability of 1000-1500 J/kg (narrow and skinny profiles) while
this is leading to confluence through the ascent layer in the
850-500mb layer. CIRA LPW suggests an additional third to half
inch and quarter to third of an inch in those mid-levels to
support overall depth of 1.75 to near 2" along the Gulf coast. So
once again, strong moisture flux convergence aided by unstable air
has developed into a squall line with cells likely to increase
from 1.25 to 1.5-2"/hr as the line reaches deeper moisture further
east. Additionally, the southerly moist flow is expanding
scattered isentropically forced cells between the exiting
convective cluster and the approaching line. These more scattered
cells will be a tad shallower, but with solid flux should be still
prolific in rainfall capability even if more scattered/random in nature...adding .5-1" prior to the main line. This WAA appears to
be trending northward toward relatively drier locations and may
start to stall/flatten to southwest steering as it nears the coast
across N Kenedy, Kleberg and Nueces county. Spots of 2-3" are
possible across this northern area that may initiate some
localized flash flooding concerns, especially near the Corpus
Christi urban areas that are particularly prone to intense rates.

Additionally, upper level jet diffluence remains extreme across
far southeast TX and the lower Rio Grande Valley with 60-70kt
speed max jet lifting northward across south Texas, while the core
of the sub-tropical jet streak is fairly flat (west to east)
across northeast Mexico into the Gulf. This is over 90 degrees of
diffluence maintaining solid evacuation of convection as it moves
eastward to areas already flooded. This should also allow for
slowing of forward propagation as well as with strengthening of
the low level inflow for flanking line back-building across the
Lower Rio Grande Valley. Additional 3-5" totals across already
flooded areas; likely to maintain flash flooding conditions with
some significant flash flooding/emergency conditions to be
possible with this next round. Localized totals over 10" are
likely to become reality across a broader area of lower Rio Grande Valley.=20=20

While it is hopeful that after this MCV/forcing wave moves
through, the environment will clear out; however, there remains
quite a bit of uncertainty, as south-southeasterly flow of the
western Gulf is likely to be maintained through the peak of the
diurnal surge after prior to day break (08-10z). Intersection
with lingering outflow boundaries may still trigger additional
development, but will update the MPD later this morning to address
this concern.=20

Gallina

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-N-vDMrM6XC5gGT-Vh-2RmbLUIA-IWY7v3ZuEyPzRzoDnmQUMCzTFhqN2TzdpDopnGwJ= SVcWJD7TLFVF_FGg6OeyNKk$ for graphic product...

ATTN...WFO...BRO...CRP...

ATTN...RFC...WGRFC...NWC...

LAT...LON 28039762 27789713 27029738 26529721 25969710=20
25799726 25919782 26109845 26259881 26489914=20
26749915 27249867 27579831=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)