Subj : MESO: Mesoscale Discussion 1935 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Aug 12 2025 19:45:51 ACUS11 KWNS 121945 SWOMCD SPC MCD 121944=20 MIZ000-INZ000-ILZ000-122145- Mesoscale Discussion 1935 NWS Storm Prediction Center Norman OK 0244 PM CDT Tue Aug 12 2025 Areas affected...southern/eastern IL...western/northern IN...southwest Lower MI Concerning...Severe potential...Watch unlikely=20 Valid 121944Z - 122145Z Probability of Watch Issuance...5 percent SUMMARY...Sporadic strong gusts of 45-60 mph and generally small hail to 1 inch in diameter will be possible with a broken band of thunderstorms slowly progressing from Illinois into parts of Indiana and Lower Michigan. A Severe Thunderstorm Watch is not expected. DISCUSSION...Along a band of low-level confluence, thunderstorms have become increasingly numerous from southeast MO into southwest Lower MI. With surface temperatures of 86-91 F common ahead of this activity, to the west/north of separate convective outflow in central IN, potential for sporadic downbursts exists amid weak lower-level flow. Area VWP data indicate 0-6 km shear around 20 kts across IL into IN, to around 25 kts in southwest Lower MI. Speed change with height is largely concentrated in the mid to upper portion of the buoyancy profile. This suggests small to marginally severe hail may accompany the strongest updrafts. Loose multicell clustering may support a localized, marginal severe wind threat. Based on latest trends, this could be centered in corridors across the IL/IN/MI border area with ongoing storms near/south of Chicagoland and separately to the east-northeast of storms near/east of St. Louis. ...Grams/Smith.. 08/12/2025 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!5hXkCudAjTNjcOvTHrETxWhmzzYsmCbqMt9SaOw3VhC-029B8P8ykCq0fay5ztPW1qquZ1P5W= d0AvqgWe7lofSMfk68$ for graphic product... ATTN...WFO...IWX...GRR...IND...LOT...ILX...LSX... LAT...LON 42588622 42818602 42838532 42298496 41578551 40638690 38888858 38738939 38868968 39388949 40258868 41058804 41728729 41918683 42358633 42588622=20 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .