MD 0299 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR PORTIONS OF NORTHEAST ILLINOIS…NORTHERN INDIANA…SOUTHWEST LOWER MICHIGAN
Mesoscale Discussion 0299 NWS Storm Prediction Center Norman OK 1243 PM CDT Sun Mar 30 2025 Areas affected...Portions of northeast Illinois...northern Indiana...southwest Lower Michigan Concerning...Severe potential...Watch likely Valid 301743Z - 301945Z Probability of Watch Issuance...80 percent SUMMARY...Damaging winds will be the primary hazard with storms this afternoon. Isolated large hail may also occur. The tornado threat is less certain, but a few line-embedded circulations do appear possible. DISCUSSION...Temperatures in northeast Illinois into northern Indiana have risen into the low/mid 70s F. Cumulus along the cold front has deepened in northeast Illinois and storms appear likely to initiate as the shortwave trough moves through the region. In addition, some portion of the activity in central Illinois will move northeastward into parts of northern Indiana. Destabilization should continue through the afternoon, particularly in northern Indiana into southern Lower Michigan. MLCAPE in northeast Illinois is 500-750 J/kg and it is not clear how much more buoyancy will develop before the fast moving storms move through. The greatest risk will be strong/damaging wind gusts with what is expected to be one or more linear segments. Large hail is possible, but should be more spatially limited given storm mode. The tornado threat is less clear this far north. Low-level winds are veered and effective SRH values from objective mesoanalysis and regional VAD profiles is not large. However, the QLCS tornado threat is nonzero as line-embedded circulations are certainly possible. A watch is likely this afternoon. ..Wendt/Smith.. 03/30/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...IWX...GRR...LOT...ILX... LAT...LON 40848645 40448774 40378826 40878876 41708893 41928887 42328804 42768640 42598582 41918550 40948614 40848645 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN