ACUS11 KWNS 101853
SWOMCD
SPC MCD 101853=20
INZ000-ILZ000-IAZ000-MOZ000-102130-

Mesoscale Discussion 0187
NWS Storm Prediction Center Norman OK
0153 PM CDT Tue Mar 10 2026

Areas affected...portions of southeastern Iowa/northeastern Missouri
into northern Illinois and northwest Indiana

Concerning...Severe potential...Tornado Watch likely=20

Valid 101853Z - 102130Z

Probability of Watch Issuance...95 percent

SUMMARY...Supercell development along a surface warm front appears
likely across portions of the Midwest this afternoon, with a threat
for all severe hazards, including hail to 2+ inches in diameter and
a risk for multiple strong to intense tornadoes (EF2-3+). While the
timing of convective initiation remains somewhat uncertain, a
Tornado Watch will be needed to cover this threat within the next
1-2 hours.

DISCUSSION...Latest GOES visible satellite imagery depicts deepening
cumulus across portions of northeastern Missouri into southwestern
Iowa and western Illinois. Recent observations also show an
increasingly unstable low-level air mass characterized by low-to-mid
60s F surface dewpoints south of a warm frontal boundary. While
synoptic-scale forcing is expected to remain modest at best,
continued low-level moist advection coupled with diurnal heating and
strong mid-to-upper level flow across the Midwest are expected to
support scattered severe thunderstorm development this afternoon.

Moderate to strong instability (1500-2500 J/kg MLCAPE), steep
mid-level lapse rates of 7-8 C/km, and strong effective bulk shear
50+ kts will support a very favorable environment for intense
supercells capable of all severe hazards. Very large hail of 2+
inches in diameter will be possible initially. While low-level shear
is currently modest per the ILX 18Z special sounding and VWP, a
strengthening south-southwesterly low-level jet will favor an
accompanying strong increase in low-level shear and effective SRH
through this evening. The resultant enlarged/curved low-level
hodographs will support intense low-level mesocyclones with
supercells and an increasing risk for tornadoes (some within the
EF2-3+ range) along and immediately south of the surface warm front.
While low-level stability is expected to limit tornado potential
north of this boundary, elevated supercells that develop/persist on
the cool side of the warm front will continue to pose a threat for
large to very large hail. The timing of convective initiation
remains a bit uncertain, but a Tornado Watch will be needed within
the next 1-2 hours to cover these threats.

..Chalmers/Gleason.. 03/10/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!5P8VZp7jI9JOi5RCvJZA1FBNdq3AqfibtllqerJT5-pUHKbm_w_XyyGfl24okB359-nQyFCLa= Xn7SfdgM2GBegP9Ivc$ for graphic product...

ATTN...WFO...IWX...IND...LOT...ILX...DVN...

LAT...LON 41039205 41309188 41529106 41559007 41658890 41658791
41688721 41568648 41408623 41198615 40888630 40678675
40518715 40448741 40288838 40248898 40228965 40219039
40209104 40329153 40479192 40599207 41039205=20

MOST PROBABLE PEAK TORNADO INTENSITY...120-150 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN


=3D =3D =3D
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