Storm Prediction Center Mesoscale Discussion 2107

   Mesoscale Discussion 2107
   NWS Storm Prediction Center Norman OK
   0656 PM CDT Sun Aug 23 2026

   Areas affected...portions of Montana

   Concerning...Severe Thunderstorm Watch 617...620...

   Valid 232356Z - 240130Z

   The severe weather threat for Severe Thunderstorm Watch 617, 620
   continues.

   SUMMARY...Severe gusts remain possible across portions of MT this
   evening. Ongoing storms may gradually evolve into a linear or
   cluster or two later this evening.

   DISCUSSION...Across WW 617 and 620, several clusters of strong to
   severe storms remain ongoing this evening. The air mass downstream
   is hot and sufficiently unstable to support the ongoing storms. Some
   CAM guidance and radar trends suggest some upscale growth into one
   or more clusters is possible this evening. This appears most likely
   across northern portions of MT where more robust convection is
   ongoing. Stronger vertical shear may also support better
   organization of these storms with time. With steep lapse rates in
   the lowest several km, severe gusts remain likely this evening.

   ..Lyons.. 08/23/2026

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

   ATTN...WFO...BIS...UNR...BYZ...GGW...RIW...TFX...PIH...

   LAT...LON   45401191 46910951 49070834 49070393 44900404 44801039
               44691149 44691192 45401191 

   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN