Storm Prediction Center Mesoscale Discussion 1401

   Mesoscale Discussion 1401
   NWS Storm Prediction Center Norman OK
   0859 PM CDT Mon Jun 24 2024

   Areas affected...Portions of western and southern SD

   Concerning...Severe potential...Watch possible 

   Valid 250159Z - 250300Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Scattered thunderstorm development is expected to continue
   through this evening across portions of west central and
   southwestern SD. Large hail near 1.50-2.50" in diameter and damaging
   wind gusts near 60-70 mph are possible.

   DISCUSSION...An area of thunderstorms has developed along a
   prefrontal surface trough and cold front late this evening across
   the higher terrain of SD. This region is under a thermal mid-level
   trough, where boundary layer temperatures and dewpoints under steep
   mid-level lapse rates continue yield moderate instability and large
   CAPE within the hail growth zone. In addition, increasing flow with
   height is resulting in sufficient deep layer effective shear
   exceeding 55 kt via forecast RAP soundings.

   Elongated, linear hodographs suggest splitting thunderstorms with an
   associated hail threat will remain possible over the next 1-2 hours
   before multiple mergers and outflow boundaries interact. After
   which, later tonight, increasing isentropic ascent within the low to
   mid-levels may continue to support a cluster or two of thunderstorms
   persisting and propagating eastward off the higher terrain, with an
   accompanying damaging wind threat near the cold front. Trends will
   be monitored for a possible watch, which will depend on upscale
   growth into a bowing cluster.

   ..Barnes/Gleason.. 06/25/2024

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

   ATTN...WFO...ABR...LBF...UNR...

   LAT...LON   42780077 42680114 43350170 43540238 43760345 44180386
               44890382 45320341 45400265 45150172 45070086 44450071
               42940044 42780077