Storm Prediction Center Mesoscale Discussion 1309

   Mesoscale Discussion 1309
   NWS Storm Prediction Center Norman OK
   1030 PM CDT Sun Jun 15 2025

   Areas affected...western North Dakota

   Concerning...Severe potential...Watch likely 

   Valid 160330Z - 160530Z

   Probability of Watch Issuance...80 percent

   SUMMARY...Severe thunderstorms continue to move east across Montana
   this evening. With time, these storms will move east into North
   Dakota posing a risk for damaging winds and isolated large hail. A
   watch will likely be needed shortly for portions of North Dakota.

   DISCUSSION...Multiple clusters of severe thunderstorms continue this
   evening across eastern Montana within a strongly sheared and very
   buoyant airmass. These thunderstorms, aided by large-scale ascent
   from a shortwave trough moving through, should continue to merge
   together and grow upscale into a large MCS that progresses east into
   portions of western North Dakota. The airmass ahead of this line
   across North Dakota remains strongly sheared, and as buoyant or
   greater than areas to the west. Thus, with most-unstable CAPE
   ranging from 1000 J/kg near the Canadian border to more than 3000
   J/kg across the North Dakota/South Dakota border, thunderstorms
   should be able to persist east of Severe Thunderstorm Watch #418. A
   severe thunderstorm watch will be needed across portions of North
   Dakota.

   ..Marsh/Smith.. 06/16/2025

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

   ATTN...WFO...BIS...

   LAT...LON   45960400 49030398 48989986 45989987 45960400 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN