Mesoscale Discussion 1280
   NWS Storm Prediction Center Norman OK
   0953 PM CDT Fri Jun 13 2025

   Areas affected...Eastern MT into northeast WY and northwest SD

   Concerning...Severe Thunderstorm Watch 411...412...

   Valid 140253Z - 140430Z

   The severe weather threat for Severe Thunderstorm Watch 411, 412
   continues.

   SUMMARY...At least an isolated severe threat may continue through
   late evening. WW 411 has been extended to 10 PM MDT.

   DISCUSSION...An earlier intense supercell cluster has weakened
   slightly across southeast MT, but likely remains severe as of 0245
   UTC, and additional storms have intensified to its north and east.
   This convection across southeast MT is ongoing within a moderately
   unstable and favorably sheared environment, and will likely continue
   to pose at least an isolated severe threat through late evening. 

   There is some indication that the ongoing storms across Rosebud
   County may evolve into a larger cluster with time. While MLCINH will
   generally increase with time and eastward extent, any organized
   upscale growth could support a greater longevity of the severe wind
   and hail threat into far southeast MT and perhaps northwest SD and
   vicinity. WW 411 has been extended in time to 10 PM MDT, and trends
   will be monitored regarding the potential for any downstream watch
   issuance late tonight. 

   Farther north, a marginal supercell is ongoing across northeast MT,
   to the northeast of Glasgow. Instability is weaker in this area, but
   the KGGW VWP depicts a favorably veering wind profile, and an
   isolated severe threat could accompany this cell before it
   eventually weakens.

   ..Dean/Smith.. 06/14/2025

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

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

   LAT...LON   45320704 47210659 48620749 48630679 48580602 46600471
               45860363 44910295 44710431 44770558 44820626 45320704 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN