ACUS11 KWNS 050231

SWOMCD

SPC MCD 050231 

INZ000-ILZ000-050430-



Mesoscale Discussion 0643

NWS Storm Prediction Center Norman OK

0931 PM CDT Mon May 04 2026



Areas affected...Eastern Illinois...Far Western Indiana



Concerning...Severe potential...Watch unlikely 



Valid 050231Z - 050430Z



Probability of Watch Issuance...20 percent



SUMMARY...An isolated large hail threat may continue across eastern

Illinois for a couple more hours, and could also affect far western

Indiana. The severe threat area should remain relatively confined,

and weather watch issuance is not expected.



DISCUSSION...The latest RAP has an axis of moderate instability

located from north-central Missouri east-northeastward into

Illinois, where MLCAPE is in the 1000 to 1800 J/kg range. Convection

has recently initiated along the far eastern edge of the stronger

instability in central Illinois. The storms are being supported by

low-level warm advection and may persist for a couple more hours.

Steep mid-level lapse rates and moderate deep-layer shear, evident

on regional WSR-88D VWPs, will likely support an isolated large hail

threat. However, instability drops off quickly with eastward extent,

suggesting that any severe threat should be relatively short-lived.



..Broyles/Hart.. 05/05/2026



...Please see www.spc.noaa.gov for graphic product...



ATTN...WFO...IWX...IND...LOT...ILX...LSX...



LAT...LON   39198698 38648798 38858862 39758912 40898904 41158774

            40788697 39198698 



MOST PROBABLE PEAK WIND GUST...55-70 MPH

MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN