ACUS11 KWNS 042335 SWOMCD SPC MCD 042334 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 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 www.spc.noaa.gov 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 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