Storm Prediction Center Mesoscale Discussion 1685

   Mesoscale Discussion 1685
   NWS Storm Prediction Center Norman OK
   0952 PM CDT Mon Jul 20 2026

   Areas affected...northeast Wisconsin

   Concerning...Tornado Watch 501...

   Valid 210252Z - 210345Z

   The severe weather threat for Tornado Watch 501 continues.

   SUMMARY...The severe weather threat is expected to diminish by 04Z,
   and an additional watch is not expected.

   DISCUSSION...As of 0240Z, KGRB radar imagery showed the trailing
   extension of a broader thunderstorm complex over Green Bay and
   adjacent Door County, to the east of a weak surface front moving
   into the area from the northwest. Both the KGRB and KMKX VWPs
   indicate a gradual veering and strengthening of the low-level jet
   with the strongest warm advection and moisture flux occurring across
   Lake Michigan into lower MI. As such, the current expectation is
   that the severe weather risk will continue to spread east of the
   area through 04Z.

   It should be noted that some of the 00Z CAMs suggest the potential
   for isolated to widely scattered storm development in the 02-04Z 
   timeframe across eastern WI, so convective trends are being
   monitored for that scenario.

   ..Mead.. 07/21/2026

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

   ATTN...WFO...APX...MQT...GRB...

   LAT...LON   44348932 45348788 46178660 46498601 46178581 44508732
               44078782 44068901 44348932 

   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN