ACUS11 KWNS 042335
SWOMCD
SPC MCD 042334=20
MOZ000-ILZ000-IAZ000-050100-

Mesoscale Discussion 0641
NWS Storm Prediction Center Norman OK
0634 PM CDT Mon May 04 2026

Areas affected...portions of NORTH-central Missouri...southeastern
iowa and northwestern Illinois

Concerning...Severe potential...Watch possible=20

Valid 042334Z - 050100Z

Probability of Watch Issuance...40 percent

SUMMARY...Isolated convective development along the cold front may
continue to deepen into this evening. Damaging gusts and some hail
will be possible with clusters or transient supercells. The need for
a WW is uncertain.

DISCUSSION...As of 2330 UTC visible and radar imagery showed initial thunderstorm development was underway along western portions of the
slow-moving cold front across southern IA and northern MO.
Downstream of the front, a warm, but marginally moist air mass
exists with 1000-1500 J/kg of MLCAPE. 30-40 kt of deep-layer shear overspreading the warm sector is sufficient for storm organization
with clusters and transient supercells possible. Given the steep
lapse rates in the low and mid-levels (8-9 C/km), damaging gusts are
possible. The degree of buoyancy could also support some hail risk
with the stronger updrafts.

It remains very unclear if these initial storms will survive given
the presence of dry air throughout the boundary layer immediately
ahead of the front. Radar trends support this with updrafts and
reflectively cores being quite small. However, if sufficient
convection is able to develop and maintain, the more unstable air
mass farther south could support a severe risk ahead of the cold
front as depicted by some CAMs this evening. Given the potential for
some damaging gusts and hail, a WW is possible but highly uncertain.

..Lyons/Hart.. 05/04/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!584V8MFshnw5vl16tL9pJLqg_PX9IX5018xZMIoDW0kyIksax5lGYiOPp11gNyX8gadocUzcc= enu6M1CD5ocjkOSTXU$ for graphic product...

ATTN...WFO...ILX...LSX...DVN...SGF...DMX...EAX...

LAT...LON 40489333 41169166 40839071 40479061 39689084 38929087
38759131 38139380 38349447 38779455 39289454 39759436
40489333=20

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN


=3D =3D =3D
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