Subj : MESO: Mesoscale Discussion 1985 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Aug 18 2025 20:15:47 ACUS11 KWNS 182015 SWOMCD SPC MCD 182015=20 SDZ000-182215- Mesoscale Discussion 1985 NWS Storm Prediction Center Norman OK 0315 PM CDT Mon Aug 18 2025 Areas affected...Western South Dakota Concerning...Severe potential...Watch possible=20 Valid 182015Z - 182215Z Probability of Watch Issuance...40 percent SUMMARY...Storms may produce large hail and severe winds this afternoon. Storm coverage remains uncertain, but a watch is possible depending on convective trends. DISCUSSION...A supercell has developed and intensified in the Black Hills and is currently progressing southeastward. With 7.8 C/km mid-level lapse rate sampled by the observed 18Z RAP sounding and the storm moving into modestly greater shear, it is probable this storm will continue into the afternoon. Additional cumulus are deepening along a surface boundary in northern South Dakota. Additional storms may form within the next couple of hours. The main uncertainty will be the coverage of storms. This region is in the wake of a shortwave trough now in eastern North Dakota per water vapor imagery. That, along with rising mid-level heights, may mean storms remain isolated. Those that do develop will be capable of large hail and severe winds, especially with southern extent. ...Wendt/Mosier.. 08/18/2025 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!7PstS_ph09jpLb1qnC0Ng25xfVERGnWwd0mfegbaFHDisWcQNTLCRa64ypSNrAE8j8kBEE58l= E51W3wkzTT6yFLpnlc$ for graphic product... ATTN...WFO...ABR...UNR... LAT...LON 44020373 44520381 45590280 45460115 44790075 43730145 43520272 43720371 44020373=20 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 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) .