Mesoscale Discussion 1647
   NWS Storm Prediction Center Norman OK
   0800 PM CDT Sun Aug 30 2020

   Areas affected...eastern South Dakota...central Nebraska

   Concerning...Severe Thunderstorm Watch 475...476...

   Valid 310100Z - 310300Z

   The severe weather threat for Severe Thunderstorm Watch 475, 476
   continues.

   SUMMARY...The severe risk will continue to spread southeastward
   across WW 475 and 476. Large hail appears to be the main threat,
   with localized wind damage or a brief/weak tornado possible.

   DISCUSSION...Rapid storm development occurred along the cold front
   late this afternoon with very strong low-level convergence. Storms
   briefly thrived within the narrow instability plume across northeast
   SD, but have gradually translated southward with time into the
   warmer/more unstable air mass. 

   The most probable area for a prolonged severe risk appears to be
   over central NE where a wider warm sector/uncapped air mass exists.
   Damaging hail should remain the primary threat. Increasing capping
   will limit eastward extent. 

   Farther north, the low-level jet will also maintain favorable lift
   over SD this evening, which may allow for a gradual eastward shift
   of the severe threat area. Surface-based storms will persist for a
   time over southeast SD, but eventually should become elevated with
   hail threat as they move east of the instability axis.

   ..Jewell.. 08/31/2020

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

   ATTN...WFO...MPX...FGF...FSD...OAX...ABR...GID...LBF...GLD...

   LAT...LON   40359830 40360061 41960019 42509947 44249905 44929882
               44989847 45299793 45769768 46369729 46359591 42949738
               42959748 40359830 40340059 40359830