Mesoscale Discussion 1330
   NWS Storm Prediction Center Norman OK
   0250 PM CDT Fri Jul 24 2020

   Areas affected...Central SD...Northwest NE

   Concerning...Severe potential...Watch possible 

   Valid 241950Z - 242145Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Thunderstorm coverage is expected to gradually increase
   over central SD and northwest NE over the next several hours.
   Environment conditions support isolated to widely scattered severe
   storms capable of large hail and damaging wind gusts.

   DISCUSSION...Air mass across the northern and central Plains
   continues to destabilize ahead of subtle shortwave trough ejecting
   into the central High Plains. Temperatures have reached the mid to
   upper 90s amid upper 60s/low 70s dewpoints. These warm and moist
   conditions beneath at least modestly steep mid-level lapse rates are
   resulting in moderate to strong instability. Latest mesoanalysis
   estimates MLCAPE around 2000-2500 J/kg across much of the region.
   Recent surface analysis placed a low over northwest SD, with a
   surface trough extending southward into the NE Panhandle and
   northward through central ND. 

   The approaching shortwave trough is expected to aid in further
   eastward development of this surface trough into the more buoyant
   environment over the central northern/central Plains. Low-level
   convergence along this trough as well as modest large-scale forcing
   for ascent is expected to result in gradually increasing
   thunderstorm activity over the next few hours. An initially discrete
   mode is expected, much like what is occurring now over southeast SD,
   before development into one or more linear segments later this
   afternoon/evening. Large hail and damaging wind gusts are the
   primary severe hazards.

   ..Mosier/Goss.. 07/24/2020

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

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

   LAT...LON   44570250 45550211 45830086 44679990 41830044 41760279
               42730265 44570250