Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Sep 01 2024 05:36:13 ACUS01 KWNS 010536 SWODY1 SPC AC 010534 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Sep 01 2024 Valid 011200Z - 021200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN APPALACHIANS INTO THE MID-ATLANTIC AND PARTS OF NEW ENGLAND.... ....SUMMARY... Strong thunderstorms capable of producing damaging wind gusts are probable this afternoon across the southern Appalachians and Mid-Atlantic region, as well as across parts of southern New England. ....Synopsis... Latest water-vapor imagery depicts a deepening upper trough over the Great Lakes region with an attendant cold front noted in surface observations extending from the Great Lakes region into the central Plains. The northern portion of the cold front will continue to surge to the east in tandem with the upper trough; to the south, the front will begin to slow as it becomes increasingly frontolytic over the TN Valley and Ozark Plateau later today. Thunderstorm development will mainly be focused along this front as it impinges on a moist, weakly capped air mass currently in place from the Mid-MS River Valley into the Mid-Atlantic. More isolated thunderstorm chances are anticipated across the southern U.S. and over portions of the Southwest/Great Basin. ....Southern Appalachians/Mid-Atlantic... Initially isolated thunderstorm development is expected along the cold front as it approaches the TN Valley/southern Appalachians, but the weakly capped environment will favor additional development along convective outflows as well as orographically-initiated convection within the higher terrain of the southern Appalachians. As such, convective coverage should increase through mid-afternoon as storms propagate east into the Mid-Atlantic region. Mid-level flow on the southern periphery of the upper trough will be strong enough to support around 20 knots of effective bulk shear, which should support loosely organized convective clusters/multi-cells with an attendant risk for damaging wind gusts. Recent CAM guidance suggests central NC/VA may see the best potential for such clusters, and consequently could have a relatively higher potential for damaging winds. Further to the northeast into parts of southern New England, thunderstorm coverage is expected to be much more isolated and tied primarily to a deepening surface trough during the mid/late afternoon hours. While buoyancy will remain somewhat meager due to poor mid-level lapse rates, stronger mid-level flow in closer proximity to the upper trough may support an organized storm or two. ....Northwest New York... Consideration for a small Marginal risk area was made across far northwest NY. Forcing along the cold front will be much stronger along the international border with several CAM solutions hinting that shallow convection may accompany the front with an attendant damaging wind risk (as was observed Saturday evening across the upper Great Lakes region). However, warmer mid-level temperatures further over the Northeast should limit overall buoyancy values and casts uncertainty onto convective depth and intensity. Additionally, most CAM solutions hint that this potential will remain fairly confined to along the NY international border. Due to these concerns risk probabilities were withheld, but trends will continue to be monitored. ...Moore.. 09/01/2024 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .