Storm Prediction Center Mesoscale Discussion 1440

   Mesoscale Discussion 1440
   NWS Storm Prediction Center Norman OK
   0421 PM CDT Wed Jun 25 2025

   Areas affected...portions of eastern Montana into northeast Wyoming
   and western South Dakota

   Concerning...Severe potential...Watch unlikely 

   Valid 252121Z - 252245Z

   Probability of Watch Issuance...20 percent

   SUMMARY...A few instances of severe hail or wind may accompany the
   stronger multicell or supercell structures over the next several
   hours. However, the overall severe threat should remain isolated.

   DISCUSSION...Multiple multicells and supercells have developed and
   intensified over the last few hours given the combination of
   low-level upslope flow and diurnal heating. Surface temperatures are
   in the 70s F amid 50 F surface dewpoints over the higher terrain, to
   low 60s F dewpoints farther to the east into western SD. This
   moisture, overspread by 7-8 C/km mid-level lapse rates, yields
   1000-1500 J/kg MLCAPE amid 40 kts of effective bulk shear.
   Hodographs, evident via 21Z mesoanalysis, are mainly straight and
   elongated, suggesting that multicells and splitting supercells
   should remain the primary modes of convection. Severe wind and hail
   will be the main convective hazards, though the overall modest
   buoyancy/shear parameter space and forcing for ascent suggests that
   the severe threat should be isolated.

   ..Squitieri/Guyer.. 06/25/2025

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

   ATTN...WFO...ABR...BIS...UNR...CYS...BYZ...GGW...RIW...

   LAT...LON   44030610 45990647 47710687 48200624 48120518 47040296
               45370156 43960083 43460091 43160154 43020229 43160350
               43550467 44030610 

   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN