Storm Prediction Center Mesoscale Discussion 1901

   Mesoscale Discussion 1901
   NWS Storm Prediction Center Norman OK
   0353 PM CDT Wed Aug 14 2024

   Areas affected...central South Dakota

   Concerning...Severe potential...Watch unlikely 

   Valid 142053Z - 142300Z

   Probability of Watch Issuance...20 percent

   SUMMARY...A cluster of thunderstorms may continue to slowly evolve
   to the west and northwest of the Pierre vicinity through 5-7 PM CDT,
   accompanied by occasional small to marginally severe hail and
   locally strong surface gusts.  It is possible that the risk for
   potentially damaging wind gusts could increase later this evening. 
   However, at least until then, it appears unlikely that a severe
   weather watch will be needed.

   DISCUSSION...Within lee surface troughing, inhibition is eroding
   with continuing insolation, for a destabilizing boundary layer near
   a modest low centered near Pierre.  This is being aided by mid-level
   cooling overspreading the high plains, associated with the leading
   edge of troughing crossing the northern Rockies, which appears to be
   providing support for an evolving line of convection to the west of
   Mobridge into the Philip vicinity.

   A gradual further upscale growth appears possible during the next
   few hours, as convection acquires increasing inflow of unstable
   boundary-layer air becoming characterized by CAPE up to 2000 J/kg. 
   In the presence of south-southwesterly deep-layer mean flow on the
   order of 10-15 kt, storm motions will remain slow initially. 
   However, modest shear, aided by veering of wind fields with height,
   might slowly contribute to increasing organization into early
   evening, particularly as convective outflow supports an increasingly
   prominent surface cold pool.  Once this occurs, the risk for strong
   to severe surface gusts may begin to increase.  Until then, though,
   more localized strong surface gusts and occasional small to marginal
   severe hail appear the primary potential severe hazards.

   ..Kerr/Thompson.. 08/14/2024

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

   ATTN...WFO...ABR...BIS...UNR...

   LAT...LON   45990078 45659962 43939945 43900110 45490153 45990078