Subj : MESO: Mesoscale Discussion 1879 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Aug 11 2024 18:18:20 ACUS11 KWNS 111818 SWOMCD SPC MCD 111817=20 NEZ000-SDZ000-112015- Mesoscale Discussion 1879 NWS Storm Prediction Center Norman OK 0117 PM CDT Sun Aug 11 2024 Areas affected...Portions of southwestern SD and northwestern NE Concerning...Severe potential...Watch possible=20 Valid 111817Z - 112015Z Probability of Watch Issuance...40 percent SUMMARY...Portions of southwestern South Dakota into northwestern Nebraska are being monitored for a possible Severe Thunderstorm Watch. DISCUSSION...Isolated to widely scattered thunderstorms are evolving over far northeastern WY and over the Black Hills early this afternoon -- likely aided by ascent preceding a midlevel shortwave trough (and associated MCV) tracking eastward across southwest MT, and heating over the higher terrain. Continue diurnal heating/destabilization amid middle/upper 50s to lower 60s dewpoints will continue to erode boundary-layer inhibition and contribute to 500-1000 J/kg MLCAPE. This, coupled with long/mostly straight hodographs (around 40-45 kt of effective shear), will support a gradual increase in thunderstorm intensity/organization through the afternoon. The primary concern with any initial semi-discrete/splitting supercell structures is large hail (generally 1.5-1.75 inches) and locally severe gusts. Thunderstorms will generally track southeastward into northwestern Nebraska through the afternoon, where continued heating will support a corridor of sufficient (albeit weak) surface-based instability for a continued severe risk.=20 There is uncertainty on the overall coverage of severe thunderstorms across the area, and the need for a watch is uncertain. ...Weinman/Hart.. 08/11/2024 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!6jiWfxt0dzRKReVEEkL1C8NbeKyXZ8Dt-33l9vmz6RrfzI43RG4AMl_bPkeHDQEa_XlJvCTt0= L_K2H4xFmOGi_qwMio$ for graphic product... ATTN...WFO...LBF...UNR...CYS... LAT...LON 43810397 44330401 44510388 44650348 44600304 44410225 44060146 43400067 42800059 42200073 41920133 41770240 41950340 42380361 43370387 43810397=20 =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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .