Mesoscale Discussion 0951
   NWS Storm Prediction Center Norman OK
   0437 PM CDT Sun Jun 02 2019

   Areas affected...Far northeast Wyoming...Southwest South Dakota and
   far northwest Nebraska

   Concerning...Severe potential...Watch likely 

   Valid 022137Z - 022230Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Additional storm development is expected into the evening.
   A severe thunderstorm watch will likely be needed.

   DISCUSSION...A long-lived supercell with a history of producing very
   large hail developed over the Black Hills and has moved
   southeastward. While deep layer shear remains weak (25 knots per UDX
   VWP), MLCAPE around 1500 to 2000 J/kg and mid-level lapse rates in
   excess of 8C/km have proven sufficient for severe hail. Additional
   storms are expected to form near and ahead of this storm currently
   located in southeast Custer County. The primary threat from these
   storms will large hail with an increasing severe wind threat as
   storms congeal. Northwest of this ongoing storm, additional storms
   may try to develop over the Black Hills, but it remains uncertain
   whether any additional storms can develop with the same intensity of
   this earlier storm. 

   A severe thunderstorm watch will likely be needed for southwest
   South Dakota and northwest Nebraska to cover the threat from the
   ongoing supercell and any additional development.

   ..Bentley/Grams.. 06/02/2019

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

   ATTN...WFO...LBF...UNR...CYS...

   LAT...LON   44710444 44870406 44490305 43490188 42820152 42490237
               42570303 43260373 44160444 44710444