Storm Prediction Center Mesoscale Discussion 2117

   Mesoscale Discussion 2117
   NWS Storm Prediction Center Norman OK
   0240 PM CDT Mon Aug 24 2026

   Areas affected...south-central South Dakota into western Nebraska

   Concerning...Severe potential...Watch possible 

   Valid 241940Z - 242215Z

   Probability of Watch Issuance...60 percent

   SUMMARY...The threat for at least isolated severe storms capable of
   severe wind gusts up to 65-80 mph and large hail potentially up to
   two inches is expected to increase late this afternoon through this
   evening. A watch is possible.

   DISCUSSION...Visible satellite imagery shows a growing cumulus field
   from Ogallala north toward Merriman in western NE, in the vicinity
   of a surface trough. Additional, more elevated convection is noted
   along the SD-NE border, near Pine Ridge. The 18Z North Platte
   sounding sampled the presence of an EML with considerable capping
   for surface-based parcels. Since that observation, surface
   temperatures have warmed through the 80s into lower 90s, effectively
   reducing the amount of convective inhibition. 

   Forcing for ascent associated with a subtle short-wave trough
   currently moving through eastern WY in conjunction with continued
   daytime heating is expected locally erode the cap such that isolated
   thunderstorm development will become increasingly likely within the
   next 1-3 hours along the surface trough and/or cool front moving
   into the region from the north. The presence of steep low/mid-level
   lapse rates and a vertically veering wind profile with 30-35 kt of
   deep-layer shear will support organized storm modes, including
   supercells with an associated risk for large hail, potentially up to
   two inches and locally severe wind gusts. Latest time-lagged HRRR
   and RRFS guidance suggests that a more robust damaging wind threat
   could materialize this evening as storms merge into clusters, at
   which point gusts up to 65-80 mph would become more likely.

   ..Mead/Smith.. 08/24/2026

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

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

   LAT...LON   41610258 42400258 43400219 43890190 44090135 43870057
               43430010 42790004 41860009 41120027 40630054 40450114
               40450159 40860215 41610258 

   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN