SPC MD 1016

MD 1016 CONCERNING SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY FOR NORTHEASTERN WYOMING...SOUTHEASTERN MONTANA...WESTERN DAKOTAS 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 Read more