Storm Prediction Center Mesoscale Discussion 1016

   Mesoscale Discussion 1016
   NWS Storm Prediction Center Norman OK
   0250 PM CDT Sun Jun 07 2026

   Areas affected...northeastern Wyoming...southeastern
   Montana...western Dakotas

   Concerning...Severe potential...Severe Thunderstorm Watch likely 

   Valid 071950Z - 072145Z

   Probability of Watch Issuance...95 percent

   SUMMARY...A corridor of significant wind risk (80-100 mph) will
   emerge into afternoon/evening.

   DISCUSSION...Convection has been building across the Big Horn
   Mountains in northern Wyoming over the last 1-2 hours, with MLCIN
   slowly eroding. Consensus among hi-res guidance continues to be that
   this region will the origin of initial clustered thunderstorm
   development over the next couple of hours. Downstream ahead of a
   surface front in eastern Montana into the western Dakotas, strong
   surface heating and dew points in the low to mid 60s has yielded a
   gradient of moderate to strong MLCAPE around 1000-2500 J/kg. 18z
   observed soundings from Rapid City, SD and Bismark, ND sampled steep
   low to mid-level lapse rates around 7-8.5 C/km.

   There is good agreement and run to run consistency in hi-res
   guidance indicating convection will grow upscale out of
   Wyoming/Montana into an intense MCS into southeastern Montana and
   the western Dakotas this evening. Early WoFS runs are also coming
   into alignment with trends indicating a swath of severe to intense
   wind across this region as well. Initially, supercell clusters will
   be capable of large to very large hail before growing upscale and
   eventual evolution to primarily a wind threat. The aforementioned
   thermodynamic environment in combination with strong deep layer
   shear will promote downstream maintenance of this MCS into the late
   evening. A watch will be needed soon to cover this potential.

   ..Thornton/Smith.. 06/07/2026

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

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

   LAT...LON   43550431 43610596 44090684 44830742 45560751 46120706
               46740535 48030414 49110371 49230209 49070057 48420056
               47720065 46550092 45770117 45050199 44430258 43840355
               43550431 

   MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
   MOST PROBABLE PEAK WIND GUST...85-100 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN