Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Feb 28 2024 13:00:47 ACUS01 KWNS 281300 SWODY1 SPC AC 281259 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0659 AM CST Wed Feb 28 2024 Valid 281300Z - 291200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE APPALACHIAN STATES...AND EASTWARD TO THE EASTERN U.S. COASTAL PLAIN... ....SUMMARY... Isolated strong to severe gusts will be possible today from the west slopes of the Appalachians to western New England, the Mid-Atlantic Region, and portions of the Carolinas. ....Synopsis... Mid-level troughing over the central U.S. this morning will continue to intensify as it gradually takes on a more negative tilt, shifting eastward across the eastern third of the U.S. through tonight. Meanwhile, weak ridging will generally prevail over the West, ahead of second trough over the Gulf of Alaska digging southeastward toward the Pacific Northwest. At the surface, a strong cold front will cross the Appalachians through midday, and then continue across the eastern U.S., with the boundary moving off the Atlantic and Gulf Coasts this evening and lingering only across Florida overnight. In the West, a cold front will gradually shift southeastward into/across the Pacific Northwest. In between, high pressure will prevail across much of the country. ....Appalachian states... Showers and thunderstorms are ongoing this morning from the Lower Great Lakes region southwestward to the Mississippi Delta, along and ahead of the advancing cold front. The strongest storms are ongoing from the Upper Ohio Valley southwestward across Kentucky, where occasionally severe storms -- capable of producing damaging wind gusts and a brief tornado or two -- continue moving eastward. Instability ahead of the convection weakens with eastward extent, particularly east of the mountains. However, pockets of near-surface-based CAPE in the 250 to 500 J/kg range will be possible through this afternoon -- enough to support broken/narrow frontal convective bands until the front moves offshore this evening. Despite the very weak instability, the deep-layer wind field will remain particularly strong -- including 40 to 60 kt as low as 1km AGL and increasing with height. As such, potential for convectively enhanced mixing/downward momentum transport appears to be sufficient to suggest the possibility if isolated severe-caliber wind gusts. This warrants eastward expansion of 5% wind probability/MRGL risk through the day, with risk ending as the front moves offshore this evening. ...Goss/Broyles.. 02/28/2024 $$ = = = 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) .