Mesoscale Discussion 0821
   NWS Storm Prediction Center Norman OK
   0514 PM CDT Thu Jun 04 2020

   Areas affected...portions of northern/eastern Iowa...far southern
   Minnesota...far southeast South Dakota

   Concerning...Severe potential...Watch unlikely 

   Valid 042214Z - 042345Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Storms are developing across northern/eastern Iowa into
   far southern Minnesota. Damaging winds and large hail are the
   primary severe threats. However, given the likely isolated and
   marginal nature of the severe threat, a watch issuance is unlikely.

   DISCUSSION...Storms are developing along and near a surface front
   draped across eastern South Dakota through southwest Minnesota and
   northern Iowa. A cu field has developed across the area as
   convective temperatures are breached along with lifting associated
   with the surface front. Zonal flow aloft is strengthening and water
   vapor imagery suggests low amplitude mid-level shortwave troughs are
   rotating over the region. Daytime heating has pushed surface
   temperatures into the upper 80s F and low 90s F with dewpoints in
   the 60s F south of the front. As a result, instability has increased
   with MLCAPE of 500-1500+ J/kg now across the area per mesoanalysis,
   and weaker supercells are possible with bulk shear of 30-40 knots.
   Damaging winds and large hail are the main threats as storms drift
   eastward. However, the environment indicates the severe coverage
   will likely be more isolated with marginally severe hail/wind.

   ..Nauslar/Goss.. 06/04/2020

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

   ATTN...WFO...MKX...DVN...ARX...MPX...DMX...FSD...OAX...

   LAT...LON   41699430 42129566 42419643 43209675 44149663 44119552
               43979367 43889239 43749128 42619036 41489047 41149101
               41229241 41699430