Mesoscale Discussion 1730
   NWS Storm Prediction Center Norman OK
   0428 PM CDT Sat Aug 27 2022

   Areas affected...portions of southern into eastern Montana

   Concerning...Severe potential...Watch unlikely 

   Valid 272128Z - 272300Z

   Probability of Watch Issuance...5 percent

   SUMMARY...A couple of severe gusts may accompany the stronger
   storms. The severe threat is expected to remain isolated and a WW
   issuance is not currently anticipated.

   DISCUSSION...High-based, relatively dry thunderstorms have been
   developing atop a well-mixed boundary layer extending up to 600-500
   mb (estimated by RAP forecast soundings), driven primarily by strong
   diurnal heating and the passage of a subtle 500 mb vort max
   preceding the main trough. While buoyancy is marginal overall, 9+
   C/km lapse rates from the surface to 600-500 mb (and associated 1500
   J/kg DCAPE) will promote adequate evaporative cooling to support a
   strong, potentially severe gust threat with any stronger,
   longer-lasting storm. While mid-level westerly flow is strengthening
   appreciably over eastern MT, deep-layer shear is expected to remain
   modest at best. The mediocre CAPE/shear parameter space should limit
   the severe threat to a degree and a WW issuance is not expected.

   ..Squitieri/Grams.. 08/27/2022

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

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

   LAT...LON   45270990 46200904 46990740 47480549 47370468 46760426
               46200429 45690456 45390509 45080579 45030825 45270990