Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Jun 05 2023 06:00:34 ACUS01 KWNS 050600 SWODY1 SPC AC 050559 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Jun 05 2023 Valid 051200Z - 061200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL APPALACHIANS...DEEP SOUTH TEXAS...AND WESTERN MONTANA... ....SUMMARY... Isolated strong to severe thunderstorms may occur today across portions of the central Appalachians, deep south Texas, and western Montana. Both occasional damaging winds and hail appear possible. ....Synopsis... A mid-level trough will meander along the Northeast coastline as a second upper trough impinges on the Southwest today. Adequate low-level moisture will continue to overspread much of the western and central U.S. into the Southeast amid weak tropospheric flow, encouraging the development of at least scattered pulse thunderstorms from late morning into the evening hours. Given adequate buoyancy associated with these storms, a sparse severe gust or instance of large hail may occur. However, embedded within the broad area encompassing thunderstorm potential are a few regions where organized rounds of strong to isolated severe thunderstorms are possible. ....Central Appalachians... A mid-level impulse, embedded in the broader northwesterly flow on the backside of the aforementioned mid-level trough, will graze the central Appalachians during the afternoon. By this time, adequate boundary-layer heating will support 70+ F surface temperatures amid low 60s F dewpoints and 6.5-7.5 low to mid-level lapse rates, contributing to 2000-3000 J/kg MLCAPE. Modest speed shear above 700 mb will encourage somewhat elongated hodographs, which may promote a few organized multicellular clusters and longer-lived single cells capable of producing some large hail and a couple of strong to potentially severe gusts. ....Deep South Texas... An MCV is expected to drift slowly southward across central into southern TX through the forecast period, with an increase in thunderstorm development and intensity expected by late morning into the afternoon in tandem with surface heating. While lapse rates are not forecast to become particularly steep, 6-7 C/km tropospheric lapse rates atop mid 80s/low 70s F surface temperatures/dewpoints will contribute to 2500-3500 J/kg SBCAPE. Furthermore, some veering/strengthening of winds with height to the right of the MCV trajectory will contribute to elongated and curved hodographs. Multicellular clusters and transient supercells are possible. Large hail and damaging gusts are the main threats, though a brief tornado cannot be ruled out. ....Western Montana... A mid-level impulse will graze western MT this afternoon as the boundary layer destabilizes. While low-level moisture will be modest, 7-8 C/km low to mid-level lapse rates will contribute to tall, thin MLCAPE over 1500 J/kg. While tropospheric flow will be predominantly unidirectional, adequate speed shear will promote elongated hodographs, supporting some longer-lived, organized multicells capable of an isolated severe gust/hail threat. ...Squitieri/Goss.. 06/05/2023 $$ = = = 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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .