Storm Prediction Center Mesoscale Discussion 1997

   Mesoscale Discussion 1997
   NWS Storm Prediction Center Norman OK
   0702 PM CDT Wed Aug 20 2025

   Areas affected...portions of north-central into northeastern Montana

   Concerning...Severe potential...Watch unlikely 

   Valid 210002Z - 210230Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Isolated supercells should persist across portions of
   north-central into northeastern Montana over the next few hours,
   accompanied by a severe hail and wind threat.

   DISCUSSION...Two dominant, discrete supercells have materialized
   over the past few hours, with severe gusts reported and MRMS mosaic
   MESH data suggesting hail over 1.5 inches in diameter occurring.
   These storms are rapidly progressing eastward amid strong mid- to
   upper-level flow associated with a 300 mb jet streak. 40 kts of
   effective bulk shear is present, and is coinciding with 1000-1500
   J/kg MLCAPE, driven mainly by 8.5+ C/km mid-level lapse rates. Given
   this environment, supercells should continue eastward for at least a
   few more hours, with severe gusts potentially reaching 75 mph, along
   with 1.5+ inch diameter hail. Despite the severe conditions
   associated with these storms, the severe threat should remain
   isolated and localized, given the low coverage of storms. As such, a
   WW issuance is not currently anticipated.

   ..Squitieri/Mosier.. 08/21/2025

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

   ATTN...WFO...GGW...TFX...

   LAT...LON   47150948 47330982 47670998 48460990 48840937 48960660
               48640613 48210595 47650610 47230650 47070722 47080819
               47090889 47150948 

   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN