ACUS11 KWNS 102154 SWOMCD SPC MCD 102153 MIZ000-INZ000-ILZ000-WIZ000-IAZ000-102330- Mesoscale Discussion 0191 NWS Storm Prediction Center Norman OK 0453 PM CDT Tue Mar 10 2026 Areas affected...portions of eastern Iowa into northern Illinois and southwestern lower Michigan. Concerning...Severe potential...Watch likely Valid 102153Z - 102330Z Probability of Watch Issuance...95 percent SUMMARY...Scattered elevated supercells and bowing segments appear likely this afternoon/evening north of the east-west warm front. A risk for significant hail and damaging gusts is possible. A WW is likely needed shortly. DISCUSSION...As of 2145 UTC, mesoanalysis and radar observations showed an east-west oriented warm front stretching from eastern IA, across northern IL into southern lower MI. South of the front, temperatures in the 70s and 80s F amid mid to upper 60s F surface dewpoints are supporting moderate to large buoyancy of 2000-3000 J/kg of MLCAPE. Strong destabilization is also ongoing in an elevated manner along and north of the boundary with 1500-2500 J/kg of MUCAPE despite cooler surface temperatures. Strong mid-level flow is overspreading the boundary supporting deep veering wind profiles supportive of organized severe storms. Weak surface convergence southeast of the front has ignited several supercells across northern IL this afternoon. As storms cross out of the Tornado Watch and the front, they will become elevated. With robust buoyancy and deep-layer shear greater than 50 kt, they are likely to remain intense and capable of large to very large hail. Recent CAM guidance and surface convergence near a surface low in IA/MO suggest numerous storms will develop within the elevated regime over the next few hours. With time, these initial supercells are likely to grow upscale into elevated bows or clusters with a continued hail threat and possibly damaging winds associated with strong gravity waves propagating along the top of the stable surface layer. Given the increasing severe threat, a new WW is likely needed for eastern IA into northern IL and portions of western lower MI. ..Lyons/Hart.. 03/10/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...IWX...GRR...LOT...MKX...DVN... LAT...LON 41359124 41339201 41879171 42459083 42598948 42718788 42738720 42758604 42728566 42238543 41928552 41688609 41378815 41359124 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN