Mesoscale Discussion 0433
   NWS Storm Prediction Center Norman OK
   1105 AM CDT Tue Apr 27 2021

   Areas affected...Portions of northern/central WI and the U.P. of MI

   Concerning...Severe potential...Watch unlikely 

   Valid 271605Z - 271830Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Isolated large hail may occur with elevated storms over
   the next couple of hours. Watch issuance appears unlikely.

   DISCUSSION...A few supercells have recently developed over
   northeastern WI to the north of a surface front. These storms will
   likely remain elevated, and appear to be focused along a temperature
   gradient at 850 mb. The 12Z sounding from GRB shows the presence of
   steep mid-level lapse rates (8.3 C/km in the 700-500 mb layer),
   which is clearly supporting robust updrafts given the ongoing strong
   to severe convection. Even though low-level moisture is expected to
   remain quite limited north of the front, there is enough mid-level
   moisture combined with steep lapse rates aloft to support weak
   elevated instability. Large-scale forcing is somewhat nebulous, with
   this recent activity probably tied to a low-amplitude shortwave
   trough traversing parts of the Upper Midwest per recent water vapor
   satellite imagery. There is uncertainty with how much additional
   robust convection will develop in this regime, especially to the
   west of the ongoing storms into central WI. But, occasional large
   hail will likely remain a concern with the strongest storms in the
   short term across parts of northeastern WI and the far southern part
   of the U.P. of MI. Given expectations for a fairly isolated severe
   threat through the early afternoon, watch issuance is unlikely at
   this time.

   ..Gleason/Hart.. 04/27/2021

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

   ATTN...WFO...MQT...GRB...ARX...MPX...

   LAT...LON   44699136 44959093 45678787 45738712 45648633 45278644
               44968676 44728732 44479129 44699136