Storm Prediction Center Mesoscale Discussion 1760

   Mesoscale Discussion 1760
   NWS Storm Prediction Center Norman OK
   0940 AM CDT Mon Jul 27 2026

   Areas affected...southeast WI...northeast IL...southwest Lower
   MI...northeast IN

   Concerning...Severe potential...Watch possible 

   Valid 271440Z - 271715Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Severe potential will increase into early afternoon across
   the Lake Michigan vicinity. Timing and storm evolution is a bit
   uncertain, but a severe thunderstorm probably will be needed in the
   next few hours.

   DISCUSSION...A developing bow is currently moving across northeast
   WI. Additional convection is developing ahead of this feature to the
   southeast from Green Bay into central Lake Michigan along a moisture
   and differential heating band within stronger northwesterly flow
   aloft. Further south across parts of southern WI into northern IL,
   elevated convection and developing TCU are noted in latest radar and
   visible satellite imagery within a corridor of extreme instability.
   It is possible that multiple clusters of strong to severe storms
   could develop within these two corridors as the furthest north
   cluster also continues to intensify and develop southeast. 

   While its remains unclear exactly how the risk will evolve over the
   next few hours, it seems likely that storms will develop within a
   very unstable airmass characterized by 2000-4000 J/kg MLCAPE, very
   steep midlevel lapse rates, and 50+ kt deep-layer shear. The most
   favorable corridor through early afternoon for severe storms
   producing swaths of damaging winds and isolated hail will be from
   eastern parts of WI into northeast IL, southern/central Lake
   Michigan, and southwest Lower MI/northwest IN. Timing of watch
   issuance is uncertain, but a severe thunderstorm watch will likely
   be needed at some point by midday/early afternoon.

   ..Leitman/Hart.. 07/27/2026

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...IWX...GRR...GRB...LOT...MKX...

   LAT...LON   44948764 43908676 42968600 42508573 41988565 41148650
               41138732 41478805 42108900 42788924 43668913 44568838
               44948764 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN