Storm Prediction Center Mesoscale Discussion 1735

   Mesoscale Discussion 1735
   NWS Storm Prediction Center Norman OK
   0625 PM CDT Sat Jul 25 2026

   Areas affected...North-Central South Dakota

   Concerning...Severe Thunderstorm Watch 513...

   Valid 252325Z - 260100Z

   The severe weather threat for Severe Thunderstorm Watch 513
   continues.

   SUMMARY...Severe wind gusts from 65 to 80 mph and large to very
   large hail are possible for the next few hours across north-central
   South Dakota.

   DISCUSSION...Recent surface analysis places a low over central
   western South Dakota (about 30-40 miles east of RAP), with a subtle
   moisture gradient resulting in low-level moisture convergence to the
   north and northeast of this low. This convergence, aided by weak
   warm-air advection, has resulted in a band of thunderstorms from
   northwest into central South Dakota. The downstream airmass is
   characterized by abundant low-level moisture, very warm
   temperatures, and strong to very strong buoyancy. Moderate westerly
   flow aloft atop low-level southeasterlies results in strong vertical
   shear as well. 

   This activity is expected to persist for the next few hours,
   although an outflow boundary from the cluster over south-central
   South Dakota could impact the downstream thermodynamics. A trend
   towards a more easterly motion is anticipated as well, as storms
   grow upscale and become better aligned with the deep shear and
   instability. Severe wind gusts from 65 to 80 mph are the primary
   hazard, although large to very large hail is possible as well,
   particularly if any storm mergers occur.

   ..Mosier.. 07/25/2026

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

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

   LAT...LON   44490102 44920166 45460155 45880070 45869885 44699926
               44440009 44490102 

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