Mesoscale Discussion 1776
   NWS Storm Prediction Center Norman OK
   0656 PM CDT Wed Jul 31 2024

   Areas affected...Southeast South Dakota...Far Southwest Minnesota

   Concerning...Severe potential...Watch possible 

   Valid 312356Z - 010200Z

   Probability of Watch Issuance...60 percent

   SUMMARY...A severe threat may develop over part of southeastern
   South Dakota over the next couple of hours. The severe threat may
   also impact far southwest Minnesota later this evening. Large hail,
   damaging wind gusts and an isolated tornado threat will be possible
   with the stronger storms.

   DISCUSSION...Over the last hour, mosaic radar imagery shows the
   development of isolated strong storms about 50 to 60 statute miles
   to the southwest of Sioux Falls. The storms are located to the
   southwest of a pocket of extreme instability, where the RAP is
   analyzing MLCAPE in the 4000 to 5500 J/kg range. In addition to the
   instability, the storms are being supported by large-scale ascent
   associated with a northern Plains shortwave trough, evident on water
   vapor imagery. Short-term model forecasts including the HRRR,
   suggest that the storms will grow upscale into a larger convective
   cluster, moving into southwestern Minnesota later this evening. The
   instability, combined with moderate deep-layer shear and steep
   mid-level lapse rates (shown by the RAP), suggest that supercell
   formation will be possible. Supercells will likely be associated
   with large hail and isolated severe wind gusts. Hailstones greater
   than 2 inches in diameter will be possible. A transition to a more
   linear structure will be possible as low-level flow increases,
   especially if a cold pool can organize.

   ..Broyles/Smith.. 07/31/2024

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

   ATTN...WFO...MPX...FSD...ABR...

   LAT...LON   43269577 43009676 42999757 43019841 43049881 43109909
               43209921 43269929 43469936 43649931 43879910 44189864
               44429798 44709677 44549553 43759509 43269577