Storm Prediction Center Mesoscale Discussion 1598

   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