ACUS11 KWNS 072312
SWOMCD
SPC MCD 072312=20
SDZ000-NDZ000-MTZ000-WYZ000-080045-

Mesoscale Discussion 1018
NWS Storm Prediction Center Norman OK
0612 PM CDT Sun Jun 07 2026

Areas affected...southeastern MT...northwest South Dakota and
western North Dakota

Concerning...Severe Thunderstorm Watch 285...

Valid 072312Z - 080045Z

The severe weather threat for Severe Thunderstorm Watch 285
continues.

SUMMARY...Supercells over southeastern MT are showing initial signs
of upscale growth. An organized cluster or bow may result. The
environment is favorable for a significant damaging wind risk (gusts
greater than 75 mph) which may begin in the next 1-2 hours.

DISCUSSION...Across PDS SVR Watch #285, initial supercell clusters
have remained severe with large hail, but have shown signs of
consolidation. The environment remains strongly unstable and sheared
with MLCAPE in excess of 2500 J/kg and 45-55 kt of deep-layer shear
supporting organized and intense thunderstorms. T/TD spreads as
highs 40 degrees F will favor strong downdrafts with the potential
for severe outflow winds. This, combined with enhanced convergence
near the frontal boundary will favor numerous storm interactions and
the development of new updrafts in close proximity to the ongoing
storms.=20

Exact convective evolution remains somewhat unclear, but initial
upscale growth is likely occurring. This is supported by the change
in radar presentation of the storms over southern Custer County in
MT, with multiple strong updrafts observed and lengthening storm
motion vectors. If a sufficient cold pool can organize, a highly
organized cluster or bowing complex may result. Given the very
favorable environment, this would support a significant damaging
wind risk with gusts greater than 75 mph. CAM trends along with the aforementioned observational data suggest this is likely in the next
30-90 minutes.

..Lyons.. 06/07/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!-VmT_FqB-lI1K2VXBKaWSpwp49GERLOFuo_Cp9lpGDd6cGd_E8Rl0NfjVtksy3Rp9JzNxSwTl= XB1biR5V-06Fyd4RF0$ for graphic product...

ATTN...WFO...ABR...BIS...UNR...BYZ...GGW...

LAT...LON 46140547 46810401 46960313 46760231 46460197 45750167
44930258 44800334 44730455 44890525 45350554 45770563
46140547=20

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...75-90 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN


=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 3.28-Linux
* Origin: Capitol City Online (1:2320/107)