Storm Prediction Center Mesoscale Discussion 1305

   Mesoscale Discussion 1305
   NWS Storm Prediction Center Norman OK
   0553 PM CDT Sun Jun 15 2025

   Areas affected...Central and Eastern Montana

   Concerning...Severe Thunderstorm Watch 418...

   Valid 152253Z - 160030Z

   The severe weather threat for Severe Thunderstorm Watch 418
   continues.

   SUMMARY...Thunderstorms capable of large hail and damaging winds
   will continue to increase this afternoon. With time an evolution to
   one or more lines of thunderstorms should occur, bringing with it an
   increasing threat of damaging winds.

   DISCUSSION...Several clusters of ongoing thunderstorms are present
   across the region this afternoon, with reports of damaging winds and
   measured severe hail of 1 inch in Cascade County. The large-scale
   environment in which these storms are developing is strongly sheared
   and very buoyant, with effective-layer shear on the order of 50
   knots and mixed-layer CAPE between 1500 and 3000 J/kg. This will
   continue the potential for large hail and damaging winds.

   Thunderstorms will continue to increase in coverage and intensity
   this afternoon as large-scale ascent associated with an approaching
   shortwave trough moves across the region. With time thunderstorms
   should grow upscale into one or more clusters that will move east
   through the evening hours. As this happens a transition to an
   increasing wind threat should occur.

   ..Marsh.. 06/15/2025

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

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

   LAT...LON   45191020 46651030 47041108 46901172 47301206 47501201
               47701145 48151139 48141080 48321055 48310985 48120954
               48990945 48990406 44990405 44980598 44550599 44550734
               44720773 44970789 44980825 45190810 45220864 45590878
               45570909 45470919 45410950 45170970 45191020 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN