Mesoscale Discussion 1639
   NWS Storm Prediction Center Norman OK
   0522 PM CDT Sun Aug 04 2019

   Areas affected...Eastern MT...Western ND

   Concerning...Severe potential...Watch unlikely 

   Valid 042222Z - 050015Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Isolated strong/severe thunderstorms are possible into
   this evening. Coverage may remain too sparse for watch issuance, but
   a conditional risk for large hail and severe wind gusts will be
   present with the strongest cells.

   DISCUSSION...An isolated thunderstorm has recently developed over
   eastern MT in Garfield County, with gradually increasing cumulus
   noted elsewhere across east-central MT in the vicinity of a weak
   surface boundary. While low-level moisture is rather limited across
   this region, strong heating has resulted in decreasing MLCINH, which
   may support intensification of the ongoing storm and development of
   additional isolated cells into the early evening. MLCAPE of 500-1500
   J/kg and effective shear in excess of 40 kt will support some
   updraft rotation, with long, straight hodographs favoring a large
   hail threat with any longer-lived cells. Localized severe wind gusts
   will also be possible with steep low-level lapse rates in place. 

   With large-scale ascent generally limited across this region for the
   next few hours, storm coverage is expected to be rather limited, and
   the severe threat is expected to remain too sparse for watch
   issuance in the short term. Additional thunderstorm development is
   possible later this evening as a vorticity maximum currently moving
   across southern AB approaches this region from the west.

   ..Dean/Thompson.. 08/04/2019

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

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

   LAT...LON   47520651 47600548 47710416 47640339 47150335 46440343
               46150412 46340649 46570697 46840742 47470737 47520651