Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Aug 14 2023 05:50:01 ACUS01 KWNS 140549 SWODY1 SPC AC 140548 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Mon Aug 14 2023 Valid 141200Z - 151200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN PORTIONS OF KENTUCKY AND TENNESSEE...AND SOUTHERN OHIO...EASTWARD ACROSS THE MID-ATLANTIC REGION... ....SUMMARY... Strong/locally severe thunderstorms are expected today and into this evening across portions of the Midwest, Kentucky and Tennessee, and extending eastward to the Mid-Atlantic Region. ....Synopsis... Ridging aloft will prevail today and tonight across the western U.S., while a vigorous short-wave trough sweeps across the Great Lakes/Midwest/Ohio and Tennessee Valley regions through the period. At the surface, a weak/disorganized low is forecast to move eastward across the Midwest region, eventually consolidating somewhat overnight as it shifts across Pennsylvania. By the end of the period, the low is progged to reside in the vicinity of southeastern New York, with the trailing cold front extending southwestward along the east slopes of the Appalachians, and then west-southwestward across the Gulf Coast states and into southern Texas. ....Tennessee/Kentucky to the Mid-Atlantic region... Storms should be ongoing at the start of the period across western portions of Tennessee and Kentucky, potentially accompanied by local/limited severe risk. As this convection moves quickly eastward across the Tennessee Valley/Mid South region through midday, some redevelopment of convection east of the mountains may occur, along with the potential for an uptick in severe-weather potential. Meanwhile, in the wake of this initial round of convection heating/destabilization should occur along/ahead of the cold front which should be shifting across the Ohio Valley area during the afternoon. Given the moderately strong west-southwesterly flow through the lower and middle troposphere, organized/severe storms capable of producing primarily damaging winds are expected. Storms -- and local severe risk -- should persist into the evening, before weakening in most areas. Risk may linger through much of the period however across northern portions of the risk area -- i.e. across eastern Pennsylvania and vicinity -- nearer the expected track of the surface low where both ascent, and shear, will be maximized. ....The Midwest... As the upper trough sweeps eastward across the Midwest today, a corridor of low-level moisture is forecast to reside along and east of an inverted surface trough extending northwest-to-southeast across the Illinois/Indiana vicinity. Beneath rather steep mid-level lapse rates, daytime heating of the relatively moist boundary layer will yield modest low-topped instability (mixed-layer CAPE 500 to 1000 J/kg). With enhanced low-level shear expected along/east of the surface boundary, potential for a tornado or two with a couple of the stronger storms may evolve through midday and into the afternoon. Locally strong wind gusts and isolated instances of marginally severe hail will also be possible. ...Goss/Lyons.. 08/14/2023 $$ = = = 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) .