Subj : MESO: Mesoscale Discussion 1886 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Aug 04 2025 20:39:52 ACUS11 KWNS 042038 SWOMCD SPC MCD 042038=20 SDZ000-NEZ000-MTZ000-WYZ000-042215- Mesoscale Discussion 1886 NWS Storm Prediction Center Norman OK 0338 PM CDT Mon Aug 04 2025 Areas affected...northeast WY...southeast MT...and western SD Concerning...Severe potential...Watch possible=20 Valid 042038Z - 042215Z Probability of Watch Issuance...60 percent SUMMARY...A few supercells may develop with a threat of severe hail/wind downstream of the Big Horn Mountains and along the western/southern slopes of the Black Hills. While overall coverage/intensity should be less compared to farther south in the central High Plains, Severe Thunderstorm Watch issuance is possible in the next couple hours. DISCUSSION...Initial high-based, low-topped thunderstorms have formed along the lee of the Big Horn Mountains, with a separate arc of congested CU along the west to south flank of the Black Hills. Much of the region between and ahead of these regimes is characterized by upper 40s to mid 50s surface dew points with large temperature/dew point spreads. This is yielding more modest buoyancy relative to eastern CO and southwest NE. Still, moderate deep-layer shear should support a few high-based supercells across southwest SD into the northeast WY/far southeast MT vicinity by early evening. A mix of sporadic severe hail and wind appears possible. Expected coverage/intensity appears marginally supportive of Severe Thunderstorm Watch issuance. ...Grams/Smith.. 08/04/2025 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!8hwJurx9tG3WLCzymzAIb6LsOyBI_4rt5_kP8wf9wn6dmfdcIF2sfvPzybTMzh0Muqza8n_Z6= Bh-LXryp2VR05N3LG8$ for graphic product... ATTN...WFO...LBF...UNR...CYS...BYZ... LAT...LON 46000496 45230368 43740245 43040238 42880267 43080404 43200487 43970503 45180643 45650639 46000496=20 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .