Mesoscale Discussion 1621
   NWS Storm Prediction Center Norman OK
   0815 PM CDT Fri Aug 28 2020

   Areas affected...Southern Lower Michigan

   Concerning...Severe potential...Watch possible 

   Valid 290115Z - 290345Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Thunderstorms have increased in coverage and intensity
   over Lake Michigan and are expected to pose a severe weather threat
   as they move into southern Lower Michigan.  Convective trends will
   be monitored for the possibility of a watch.

   DISCUSSION...An upper-level impulse moving across southern Wisconsin
   has aided the initiation of storms across Lake Michigan (including a
   long-lived supercell).  These storms have increased in coverage and
   intensity with time and are expected to persist as they move
   eastward across Lower Michigan tonight.  Given a relatively
   favorable kinematic and thermodynamic environment downstream, these
   storms should remain organized (including transient supercell
   structures), posing a severe weather threat.  Some surface-based CIN
   is present (per current mesoanalysis) over southern Lower Michigan
   given the stabilizing nocturnal boundary layer, but RAP forecast
   soundings suggest effective layer inflow parcels are likely to
   originate from the surface.  Thus, damaging winds are possible along
   with hail, and a tornado cannot be ruled out.  Convective trends
   will be monitored for the possibility of a watch.

   ..Jirak/Guyer.. 08/29/2020

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

   ATTN...WFO...DTX...IWX...GRR...

   LAT...LON   43198630 43588628 43698546 43628475 43298384 42728317
               42358295 42068326 41878390 41818474 41958594 42158616
               42228628 42608619 42998619 43198630