Mesoscale Discussion 0962
   NWS Storm Prediction Center Norman OK
   0909 PM CDT Sun Jun 21 2020

   Areas affected...Portions of southeast Minnesota...northeast
   Iowa...western Wisconsin

   Concerning...Severe potential...Watch unlikely 

   Valid 220209Z - 220415Z

   Probability of Watch Issuance...20 percent

   SUMMARY...A couple damaging gusts, with perhaps a severe gust or
   two, remain possible with the ongoing squall line. However, diurnal
   cooling and waning instability should limit the ongoing threat. The
   isolated nature of the severe threat suggests that a new WW issuance
   is not necessary.

   DISCUSSION...An organized MCS/squall line is ongoing across
   northeast IA into western WI. A few severe gusts have been reported
   over the past two hours across northeast IA. A narrow corridor of
   adequate instability (around 1000 J/kg MLCAPE per latest
   Mesoanalysis) resides immediately ahead of the line, suggesting that
   a few damaging gusts, perhaps one or two approaching severe levels,
   remains possible over the next couple of hours. While the 00Z DVN
   sounding had indicated up to 1300 J/kg MLCAPE, modifying this
   sounding based on current surface temperatures (roughly in the mid
   70s F) shows MLCAPE within the 500-1000 J/kg range. Further
   nocturnal cooling should contribute to boundary-layer decoupling and
   associated gradual decline in severe potential, even if squall-line
   structure persists. 

   The ongoing squall outrunning the instability axis, along with
   boundary-layer stabilization suggest that the severe threat should
   be relatively sparse and brief in nature. As such, a future WW
   issuance is not anticipated.

   ..Squitieri/Thompson.. 06/22/2020

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

   ATTN...WFO...GRB...MKX...DVN...DLH...ARX...MPX...DMX...

   LAT...LON   42669386 44179182 45269056 45668954 45638909 45028918
               43998911 43108953 42709029 42469068 42159112 42369332
               42669386