Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed May 17 2023 19:40:31 ACUS01 KWNS 171940 SWODY1 SPC AC 171939 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0239 PM CDT Wed May 17 2023 Valid 172000Z - 181200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND EVENING ACROSS PARTS OF THE SOUTHEAST AND THE GREAT PLAINS... ....SUMMARY... Localized damaging wind gusts remain possible in scattered storms across parts of the Southeast into early evening. Sporadic severe hail and wind gusts also remain possible with increasing thunderstorm activity across parts of the Dakotas into the southern High Plains through this early evening. ....20Z Update... Some adjustments have been made to the categorical and probabilistic lines, mostly to account for the progression of synoptic/sub-synoptic features and their influence on instability trends. Across the Southeast, the Gulf sea breeze and an assortment of outflow boundaries continue to spread inland of coastal areas. Deep-layer westerly ambient mean flow continues to weaken and (based on the latest Rapid Refresh), outside a broadening corridor across Georgia into the Carolinas, is now generally on the order of 15 kt or less. However, thermodynamic profiles with moderately steep low-level lapse rates may continue to support a risk for localized damaging wind gusts as thunderstorm activity becomes increasingly widespread through late afternoon. ...Kerr.. 05/17/2023 ..PREV DISCUSSION... /ISSUED 1056 AM CDT Wed May 17 2023/ ....Southeast... Scattered thunderstorms are expected this afternoon from the Gulf Coast to a slow-moving cold front undergoing frontolysis across parts of the Deep South. Per 12Z observed soundings and visible satellite imagery, the strongest boundary-layer heating and MLCAPE should develop across southern portions of MS/AL/GA/SC, with more limited values to the north. Weak deep-layer shear and lapse rates (around 5.5-6 C/km from 700-500 mb) will mitigate organization potential and hail growth across much of the region. Pockets of marginally severe hail potential around 1 inch are possible in the most buoyant airmass over the central Gulf Coast and with somewhat greater deep shear across southern SC. Otherwise, sporadic wet microbursts producing strong gusts capable of tree damage should be the primary threat. ....Dakotas to southern High Plains... Isolated to scattered thunderstorms will be focused this afternoon along a southeast-moving cold front over the Dakotas, and southward along a lee trough to the southern High Plains. Mid-level west-northwesterlies will be weak, but strengthen with height into the upper-levels across the central High Plains and support potential for a few transient supercell structures. Though convective coverage here should be relatively less compared to farther north and south. Modest MLCAPE of 1000-1500 J/kg should develop over the southern High Plains along the northwest periphery of PW values around 1 inch, with weak buoyancy farther north. Overall setup should support sporadic instances of lower-end severe hail and wind. $$ = = = 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) .