Mesoscale Discussion 1637
   NWS Storm Prediction Center Norman OK
   0621 PM CDT Sat Aug 03 2019

   Areas affected...Southwest ND...Western SD...Northeast WY

   Concerning...Severe potential...Watch unlikely 

   Valid 032321Z - 040115Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Isolated supercells capable of large hail and localized
   severe wind gusts will remain possible into mid evening before
   weakening. Watch issuance is unlikely due to limited coverage and
   duration of the threat.

   DISCUSSION...Widely scattered strong thunderstorms are ongoing
   across portions of the northern High Plains at 2315Z, with the
   strongest storm across southwest ND displaying supercell
   characteristics. Moderate instability (MLCAPE of 1500-2000 J/kg) and
   sufficient effective shear (40-50 kt) will support the potential for
   supercell structures with ongoing convection in the short term,
   though storms are expected to remain widely scattered given limited
   large-scale ascent across the region. Large hail and locally severe
   wind gusts will be the primary threats. 

   Increasing MLCINH with eastward extent will limit the potential for
   supercells to spread very far downstream, though cells that develop
   more rightward motion (like the cell in southwest ND) will have a
   longer residence time within a weakly capped environment and have
   greater potential to persist for another 1-2 hours across western
   SD. An eventual weakening trend for any remaining cells is expected
   later this evening in conjunction with diurnal
   cooling/stabilization. Due to the limited coverage and duration of
   the severe threat, watch issuance is unlikely.

   ..Dean/Thompson.. 08/03/2019

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

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

   LAT...LON   44070515 44950384 45910374 46750342 46700267 46150234
               45180250 44360284 43860300 43610430 44070515