265  
ACUS11 KWNS 121237  
SWOMCD  
SPC MCD 121236  
MIZ000-MNZ000-121430-  
 
MESOSCALE DISCUSSION 1598  
NWS STORM PREDICTION CENTER NORMAN OK  
0736 AM CDT SUN JUL 12 2026  
 
AREAS AFFECTED...PORTIONS OF THE UPPER PENINSULA OF MICHIGAN  
 
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE  
 
VALID 121236Z - 121430Z  
 
PROBABILITY OF WATCH ISSUANCE...40 PERCENT  
 
SUMMARY...SUPERCELLS MAY TRACK SOUTHWARD THROUGH THE MORNING WITH  
POTENTIAL FOR LARGE HAIL AND DAMAGING WIND.  
 
DISCUSSION...A SUPERCELL IS TRACKING SOUTHWARD ACROSS LAKE SUPERIOR  
TOWARDS THE KEWEENAW PENINSULA. THERE IS SOME UNCERTAINTY IN HOW FAR  
SOUTH THIS STORM WILL BE SUSTAINED, AS AN ADDITIONAL SUPERCELL TO  
THE NORTH WEAKENED QUICKLY. OVERNIGHT GUIDANCE HAS HANDLED THE  
EVOLUTION OF THESE STORMS POORLY, LEADING TO LOW CONFIDENCE IN MORE  
RECENT RUNS. THE ENVIRONMENT DOWNSTREAM HAS BEEN STEADILY BECOMING  
MORE UNSTABLE, WITH AN EML ADVECTING EASTWARD ACROSS THE REGION.  
CURRENTLY, TEMPERATURES DOWNSTREAM OF LAKE SUPERIOR ACROSS THE UP OF  
MICHIGAN ARE COOLER, IN THE UPPER 60S TO 70S WITH DECREASING  
INSTABILITY/DEEP LAYER SHEAR TO THE SOUTH FURTHER INLAND. IT IS  
POSSIBLE THAT THIS INITIAL WAVE OF STORMS MAY WEAKEN AS THEY MOVE  
INLAND. CUMULUS IS DEEPENING TO THE NORTH OF THESE INITIAL CELLS  
ACROSS SOUTHERN ONTARIO, WHICH MAY LEAD TO ADDITIONAL THUNDERSTORM  
DEVELOPMENT OVER THE NEXT COUPLE OF HOURS. TRENDS WILL BE MONITORED  
BUT FOR NOW THE SEVERE POTENTIAL APPEARS TO BE ISOLATED.  
 
..THORNTON/GLEASON.. 07/12/2026  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...MQT...DLH...  
 
LAT...LON 47488921 47948957 48238953 48478931 48608876 48428788  
48238753 47838722 47588719 47278718 46968724 46738742  
46658782 46878853 47048892 47138902 47488921  
 
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH  
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN  
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