Mesoscale Discussion 1680
   NWS Storm Prediction Center Norman OK
   0647 PM CDT Sun Sep 06 2020

   Areas affected...Eastern WI...Lower MI

   Concerning...Severe potential...Watch possible 

   Valid 062347Z - 070145Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Robust convection may develop across eastern WI into lower
   MI over the next few hours. Hail is the primary risk with this
   activity. Some consideration for a severe thunderstorm watch is
   necessary.

   DISCUSSION...Early-evening satellite imagery depicts a short-wave
   trough over the upper Great Lakes moving east-southeast toward lower
   MI. Extensive, layered cloudiness is noted ahead of this feature
   along with relatively stable boundary-layer conditions due to weak
   recovery in the wake of the early-day MCS that spread across
   northern IL. Over the last few hours it appears some recovery is
   occurring aloft within veered flow ahead of the front across IA into
   central WI. Earlier CAMs suggested strong convection would be under
   way by now across eastern WI. This delay may be due in part to the
   early-day MCS and retarded destabilization. Even so, a strong 500mb
   speed max is translating across south-central WI at this time and
   high-level diffluence should prove encouraging for deep convection.
   Over the last half hour, or so, a new shower has developed west of
   Fond du Lac WI and this may be the start of a more expansive cluster
   of storms that would spread across Lake MI into lower MI later this
   evening. Forecast soundings suggest convection will be rooted at, or
   near, 850mb and thus hail would be the primary risk. Severe
   thunderstorm watch may be warranted in the next hour or so
   downstream.

   ..Darrow/Hart.. 09/06/2020

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

   ATTN...WFO...DTX...APX...GRR...GRB...MKX...

   LAT...LON   44208839 44668448 43368421 42878809 44208839