Storm Prediction Center Mesoscale Discussion 1761

   Mesoscale Discussion 1761
   NWS Storm Prediction Center Norman OK
   1216 PM CDT Mon Jul 27 2026

   Areas affected...east-central WI

   Concerning...Severe Thunderstorm Watch 519...

   Valid 271716Z - 271845Z

   The severe weather threat for Severe Thunderstorm Watch 519
   continues.

   SUMMARY...Very large hail and tornado potential may persist the next
   1-2 hours as a cell near Winnebago and Calumet counties continues
   southeast.

   DISCUSSION...A supercell over far northeast Winnebago and Calumet
   counties likely produced a damaging tornado recently based on strong
   rotation and TDS from KGRB radar. The downstream airmass remains
   very unstable with effective layer STP approaching 4 to 6 in a
   corridor southeast of ongoing storms. Given steep lapse rates,
   favorable thermodynamics and strong effective shear greater than 50
   kt supporting continued supercell structures, a risk for very large
   hail up to 2.5 inches and a continued risk of strong tornadoes may
   continue for another 1-2 hours.

   ..Leitman.. 07/27/2026

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

   ATTN...WFO...GRB...MKX...

   LAT...LON   44028760 43758746 43498751 43438780 43528823 43998868
               44308875 44358815 44348807 44298798 44028760 

   MOST PROBABLE PEAK TORNADO INTENSITY...100-125 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN