Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jan 04 2023 05:42:44 ACUS01 KWNS 040542 SWODY1 SPC AC 040541 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1141 PM CST Tue Jan 03 2023 Valid 041200Z - 051200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHEAST... ....SUMMARY... Strong to severe thunderstorms are possible today over portions of the Southeast into the Carolinas and southeast Virginia. Strong gusts and a couple of tornadoes will be possible, mainly over parts of Georgia, Alabama, and Florida. ....Synopsis... An upper low will move slowly from the upper MS Valley toward the upper Great Lakes today, with a broad upper trough across much of the East. A leading speed max will eject northeastward across the TN/OH valleys during the day and into the Northeast overnight, resulting in slow height falls over the Southeast. Behind this feature, a secondary wave will develop across TX and into the lower MS Valley overnight, over a stable air mass. At the surface, an effective cold front will move across the Appalachians during the day, extending southwestward into the northeastern Gulf of Mexico through 00Z. Upper 60s F dewpoints will be common ahead of the front and ongoing convection from southern GA into FL, with low to mid 60s developing north into the Carolinas and southeast VA. Southwesterly 850 mb winds of 40-50 kt will be common over the region, aiding wind potential but also drying from the southwest over time. To the west, a deep cyclone will approach the Pacific Northwest, providing widespread precipitation including a few thunderstorms as a cold front approaches late. ....Southeast... Storms are likely to be ongoing along the from the FL Panhandle into southeast AL and into southwest GA. Instability is forecast to be maximized early on Wednesday, from southern GA into northern FL. Here, SRH over 200 m2/s2 along with deep-layer shear over 40 kt will favor supercells, with a tornado risk. A mitigating factor to tornado risk may be limited heating/modest low-level lapse rates beneath a warm layer above 850 mb. With time, large-scale ascent may weaken as the upper wave passes to the north. Elsewhere, MLCAPE < 1000 J/kg may develop over the Carolinas, with moderate southwesterlies aloft. A few strong to severe storms may occur during the day, focused along possible outflow boundaries or associated with ongoing convection approaching from the southwest. ....Coastal central/northern CA... Strong height falls will occur tonight along the West Coast as a deep/vertically stacked low approaches offshore. Strong warm advection will occur just off the surface and well ahead of the cold front, resulting in widespread precipitation throughout the day over much of central and northern CA. As cooling aloft persists overnight, profiles will eventually become conducive for SBCAPE to develop, primarily along the coastal counties of central/northern CA. This is forecast to occur after 03Z, and there may be a window of time where shear profiles remain strong coincident with SBCAPE around 100-200 J/kg after 06Z. As such, convectively enhanced wind gusts may occur, as flow just off the surface will likely exceed 50 kt. ...Jewell/Wendt.. 01/04/2023 $$ = = = 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) .