273  
ACUS11 KWNS 040840  
SWOMCD  
SPC MCD 040840  
MIZ000-OHZ000-INZ000-041045-  
 
MESOSCALE DISCUSSION 2231  
NWS STORM PREDICTION CENTER NORMAN OK  
0340 AM CDT FRI SEP 04 2026  
 
AREAS AFFECTED...PORTIONS OF SOUTHERN LOWER MICHIGAN  
 
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE  
 
VALID 040840Z - 041045Z  
 
PROBABILITY OF WATCH ISSUANCE...40 PERCENT  
 
SUMMARY...AN ORGANIZING CONVECTIVE CLUSTER/MCS MAY PRODUCE SEVERE  
WIND GUSTS OR SOME HAIL OVERNIGHT AND CONTINUING INTO THE MORNING. A  
WATCH IS POSSIBLE BUT UNCERTAIN.  
 
DISCUSSION...RECENT RADAR TRENDS WITH A CONVECTIVE CLUSTER OVER  
EASTERN WI POINT TOWARD ORGANIZATION INTO AN MCS POTENTIALLY CAPABLE  
OF SEVERE GUSTS AND HAIL IN THE COMING HOURS. CONTINUED LOW-LEVEL  
WARM AIR ADVECTION AT THE NOSE OF A 30-40 KT LOW-LEVEL JET HAS  
SUPPORTED AN INCREASE IN CONVECTIVE COVERAGE ACROSS EASTERN WI WHERE  
CLOUD TOP COOLING HAS BEEN NOTED. THIS HAS LIKELY STRENGTHENED A  
PREEXISTING COLD POOL WITH THE LEAD ELEMENTS OF THIS CONVECTIVE  
COMPLEX. THESE STORMS WILL CROSS THE LAKE AND MOVE INTO LOWER MI IN  
THE NEXT 1-2 HOURS. THE AIR MASS DOWNSTREAM REMAINS MODERATELY  
UNSTABLE AND SHEARED ALOFT SOUTH OF A WARM FRONT. DESPITE THE  
BUOYANCY LIKELY BEING ELEVATED ABOVE THE IMMEDIATE SURFACE STABLE  
LAYER, THE ENVIRONMENT IS MORE THAN SUFFICIENT TO MAINTAIN  
INTENSITY/ORGANIZATION OF THE ONGOING STORMS. THIS SUGGESTS SEVERE  
WIND GUSTS AND SOME HAIL ARE POSSIBLE AS CONVECTION MOVES ACROSS THE  
LAKE, INTO LOWER MI AND EVENTUALLY OH/IN LATER THIS MORNING.  
 
IT REMAINS UNCLEAR IF THE STRONGER GUSTS FROM THIS CLUSTER WILL MAKE  
IT TO THE SURFACE. THE STRENGTHENING COLD POOL, MORE ORGANIZED  
LINEAR MODE AND RECENT CAM GUIDANCE SUGGEST IT'S POSSIBLE. GIVEN THE  
POTENTIAL INCREASE IN SEVERE THREAT, CONDITIONS ARE BEING CLOSELY  
MONITORED FOR A SEVERE THUNDERSTORM WATCH.  
 
..LYONS/MOSIER.. 09/04/2026  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
 
 
ATTN...WFO...CLE...DTX...IWX...GRR...  
 
LAT...LON 42038339 41908336 41758348 41708376 41678439 41688524  
41848593 42058645 42178672 42528707 42898733 43118731  
43338722 43608706 43688651 42258366 42038339  
 
MOST PROBABLE PEAK WIND GUST...55-70 MPH  
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN  
 
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