Mesoscale Discussion 1041
   NWS Storm Prediction Center Norman OK
   0618 PM CDT Sun Jun 28 2020

   Areas affected...Northeast WY...Southeast MT...Western SD

   Concerning...Severe Thunderstorm Watch 313...

   Valid 282318Z - 290115Z

   The severe weather threat for Severe Thunderstorm Watch 313
   continues.

   SUMMARY...Scattered severe will continue across the northern High
   Plains this evening.

   DISCUSSION...Strong boundary-layer heating appears to be the primary
   instigator in strong convective development across WY into the Black
   Hills region late this afternoon. Several robust updrafts, with
   severe hail, are moving into western SD at roughly 30-35kt. This
   activity will encounter increasingly moist/buoyant air mass over the
   next hour or so, and strengthening is possible if convection is able
   to ingest boundary-layer air mass characterized by upper 50s surface
   dew points.

   Upstream, high-based convection is gradually deepening across
   central WY, well west of higher instability. Steep lapse rates
   should allow this quick-moving activity to spread back into southern
   portions of the watch later this evening. Strengthening is most
   likely to occur farther downstream near the Black Hills.

   ..Darrow.. 06/28/2020

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

   ATTN...WFO...UNR...BYZ...

   LAT...LON   43570596 45900559 45920245 43580296 43570596