131 ACUS11 KWNS 081903 SWOMCD SPC MCD 081903 NEZ000-KSZ000-COZ000-WYZ000-082100- Mesoscale Discussion 1542 NWS Storm Prediction Center Norman OK 0203 PM CDT Wed Jul 08 2026 Areas affected...portions of the central High Plains Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 081903Z - 082100Z Probability of Watch Issuance...80 percent SUMMARY...Scattered, high-based thunderstorms will bring a risk for severe wind gusts (with a couple of significant gusts possible) and isolated large hail this afternoon and evening. One or more Severe Thunderstorm Watches will likely be needed later this afternoon. DISCUSSION...Latest GOES visible satellite imagery depicts scattered thunderstorm development ongoing across the high-terrain from central Colorado northward into southeastern Wyoming. Aided by ascent ahead of a weak mid-level perturbation, continued heating and a modest upslope (easterly) wind component will continue to support the development of scattered, high-based thunderstorms through the afternoon. While moisture remains limited in the Colorado foothills (dewpoints in the 40s per latest surface analysis), deep-layer westerly flow will allow maturing convection to gradually interact with increasing moisture with eastward extent, which should promote gradual intensification with time. Steep low-level lapse rates (9+ C/km) and deep, well-mixed boundary layer profiles (LCLs of 2-3+ km) will promote efficient evaporative cooling and downward momentum transport, yielding a threat for primarily severe wind gusts (with a couple of significant wind gusts possible). Upscale growth into one or more linear clusters/segments is expected with time as cold pools gradually coalesce, yielding an increasing threat for severe wind gusts into this evening. With steep mid-level lapse rates in place, isolated large hail will also be possible (especially with any storms that are able to remain discrete) owing to modest strengthening of upper-level flow and elongation of hodographs with time. This potential will be locally greater farther to the north where better effective shear is already noted per latest mesoanalysis. One or more Severe Thunderstorm Watches will likely be needed in the next 1-2 hours to cover these threats. ..Chalmers/Hart.. 07/08/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...DDC...GLD...PUB...BOU...CYS... LAT...LON 42760372 42780293 42630256 42330206 41640176 40330163 39080166 38470177 38050201 37920228 37940272 38300351 39230413 40770465 41970469 42400445 42760372 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN  932 ACUS11 KWNS 081940 SWOMCD SPC MCD 081939 SDZ000-MTZ000-WYZ000-082145- Mesoscale Discussion 1543 NWS Storm Prediction Center Norman OK 0239 PM CDT Wed Jul 08 2026 Areas affected...portions of southeastern Montana and northern Wyoming into far western South Dakota Concerning...Severe potential...Watch possible Valid 081939Z - 082145Z Probability of Watch Issuance...40 percent SUMMARY...Widely scattered, high-based thunderstorms will pose a risk for damaging/severe wind gusts and isolated large hail this afternoon and evening. Trends are being monitored for a potential Severe Thunderstorm Watch. DISCUSSION...Scattered, high-based thunderstorm development is ongoing across the high-terrain of southern Montana and northern Wyoming as of 1930 UTC. Continued insolation amid modest low-level moisture (dewpoints ranging from the mid-40s to low-50s F) will continue to support an increase in thunderstorm coverage through the afternoon. Modifying the 18z RIW observed sounding for recent observations depicts steep low- and mid-level lapse rates with MLCAPE of 500-1000 J/kg. This dry boundary layer profile will support efficient evaporative cooling and cold pool development, with recent high-res guidance continuing to suggest the development of one or more linear clusters/segments through the afternoon. As this occurs, an increase in the threat for damaging/severe wind gusts is expected as convection progresses eastward amid deep-layer westerly flow. Isolated large hail also cannot be ruled out with the strongest cores given steep mid-level lapse rates and modest effective shear of 25-30 kts. While the general expectation is for the severe risk to remain more limited in coverage compared to areas farther south across the central High Plains, a Severe Thunderstorm Watch may be needed in the next 1-2 hours should a corridor of greater severe potential become evident. ..Chalmers/Hart.. 07/08/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...UNR...BYZ...RIW... LAT...LON 43530526 43480807 43680886 43990968 44441043 44741072 45031085 45591070 45831015 46090865 46020696 45590542 45100404 44730370 44260363 43900375 43670431 43530526 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN