Mesoscale Discussion 1328
   NWS Storm Prediction Center Norman OK
   0834 PM CDT Thu Jul 23 2020

   Areas affected...Far Northeastern Montana...Western North Dakota

   Concerning...Severe Thunderstorm Watch 397...

   Valid 240134Z - 240330Z

   The severe weather threat for Severe Thunderstorm Watch 397
   continues.

   SUMMARY...An isolated severe threat is expected to continue across
   far northeast Montana and western North Dakota for another hour or
   so. Isolated large hail and wind damage will be the primary threats.
   Weather watch issuance will probably not be needed beyond the 03Z
   expiration time of WW 397.

   DISCUSSION...The radar imagery shows a cluster of strong
   thunderstorms from far northeastern Montana extending
   south-southeastward into far western North Dakota. The storms are
   located along the western edge of a strongly unstable airmass with
   the RAP estimating MLCAPE in the 2000 to 3500 J/kg range. The storms
   are also located just ahead of a shortwave trough that is moving
   northeastward through the northern High Plains. The instability and
   large-scale ascent should be enough to keep thunderstorms going for
   a few more hours. Moderate deep-layer shear, evident on regional
   WSR-88D VWPs will be sufficient to maintain a severe threat for
   another hour or two. But the threat should become more isolated with
   time as instability begins to decrease across the northern Plains
   this evening. For this reason, additional weather watch issuance is
   not expected.

   ..Broyles.. 07/24/2020

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

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

   LAT...LON   49050436 48800459 48090406 47890408 47220415 46900380
               47440260 49010322 49050436