Mesoscale Discussion 1457
   NWS Storm Prediction Center Norman OK
   0529 PM CDT Sat Jul 13 2019

   Areas affected...Portions of northern North Dakota

   Concerning...Severe potential...Watch unlikely 

   Valid 132229Z - 132345Z

   CORRECTED FOR WORDING

   Probability of Watch Issuance...20 percent

   SUMMARY...An isolated severe risk exists with a supercell
   approaching the U.S/Canada border. Large hail is the main concern,
   though a few damaging gusts and perhaps a tornado are also not out
   of the question. Given the very sparse and localized nature of the
   severe threat, a WW issuance is not expected at this time.

   DISCUSSION...A supercell has recently developed and matured in a
   relatively weakly forced environment, characterized by modest deep
   layer ascent. Nonetheless, this storm has become sustained within an
   ambient environment characterized by ample buoyancy (up to 2500 J/kg
   MLCAPE) and deep-layer shear (40+ knots bulk-effective shear). Low
   level directional and speed shear are quite modest, leading to
   nearly straight hodographs which promote splitting supercells. The
   supercell approaching eastern Burke/western Renville counties in ND
   is the result of the right split, and has shown some indication of
   containing large hail (potentially approaching 2.0 inches in
   diameter) per latest scans of the KMBX radar data, and MRMS data
   showing 60+ dBZ cores extending past the -20C layer. Damaging gusts
   may also occur with forward and rear-flank downdrafts. Despite the
   meager directional shear, a tornado cannot be ruled out given
   favorable storm mode and buoyancy in place.

   Little evidence is in place for additional convective development,
   and given the sparse and localized nature of the current severe
   threat, a WW issuance is not currently anticipated.

   ..Squitieri/Grams.. 07/13/2019

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

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

   LAT...LON   48990264 48960023 48880013 48690008 48350037 47990082
               47690146 48640266 48990264