Subj : MESO: Mesoscale Discussion 1637 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jul 11 2025 03:36:47 ACUS11 KWNS 110336 SWOMCD SPC MCD 110336=20 ILZ000-IAZ000-110530- Mesoscale Discussion 1637 NWS Storm Prediction Center Norman OK 1036 PM CDT Thu Jul 10 2025 Areas affected...Northern Illinois Concerning...Severe potential...Watch unlikely=20 Valid 110336Z - 110530Z Probability of Watch Issuance...20 percent SUMMARY...Locally strong-severe thunderstorms will spread across portions of northern Illinois over the next several hours. Gusty winds and isolated hail are the primary threats. DISCUSSION...Low-amplitude short-wave trough is ejecting across the upper Midwest late this evening. Large-scale ascent appears to be influencing a larger complex of storms that has matured across much of northern Illinois. Additionally, low-level warm advection appears to be aiding this MCS as it tracks along the north side of a boundary, currently draped from near LAF-DVN. Latest MRMS data suggests a few hail cores are noted within the stronger updrafts along the southwestern flank of this complex, especially over southeastern Mercer County and Bureau County. Even so, hail is most likely on the order of 1 inch, or less. MCS should propagate east-southeast over the next several hours with an attendant risk for locally strong winds and isolated hail. ...Darrow.. 07/11/2025 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!5aBAtFvA870LwVwfXlXAsTNCF5so6Wlzc4Ubwo52XU-Ozkp8voc7ZRRi5MzUMSKfg1m3cgHkw= BZcCuAPBDoOC2ojdIo$ for graphic product... ATTN...WFO...LOT...ILX...DVN... LAT...LON 41518915 41278769 40358816 40969025 41509073 41518915=20 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .