Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Nov 19 2023 08:29:33 ACUS03 KWNS 190829 SWODY3 SPC AC 190828 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CST Sun Nov 19 2023 Valid 211200Z - 221200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHEAST... ....SUMMARY... Thunderstorms capable of isolated damaging wind and possibly a tornado will be possible across parts of Alabama and the Florida Panhandle on Tuesday, mainly early in the day. ....Synopsis... A deep mid/upper-level trough is expected to move across parts of the MS/OH Valleys and Southeast on Tuesday, though considerable spread remains regarding the synoptic-scale details. The primary surface cyclone is forecast to move toward the lower Great Lakes, with secondary cyclogenesis possible across parts of the Carolinas/Mid Atlantic late in the period. A cold front will continue to move through portions of the Southeast. ....Parts of AL and the FL Panhandle into southwest GA... At the start of the period Tuesday morning, rather strong low-level and deep-layer shear will likely overlap a moist and weakly unstable environment across parts of south AL and the FL Panhandle, in advance of the cold front. Storms may persist along/ahead of the front through the morning, as a continuation of widespread convection from late in the D2/Monday period. Storm intensity and coverage may tend to wane with time, as stronger large-scale ascent becomes increasingly displaced from the warm sector, and instability weakens with eastward extent. However, some threat for isolated damaging wind and a brief tornado or two may persist during the day across southeast MS, south AL, the FL Panhandle, and possibly into parts of southwest GA. ....Carolinas and southern Mid Atlantic... Substantial spread persists among model guidance with regard to the synoptic pattern late on D3/Tuesday across parts of the Carolinas and Mid Atlantic. The deterministic GFS and some GEFS members develop a mid/upper-level cyclone near the lower MS Valley, while most other guidance is notably less amplified, with a broad, positively tilted trough approaching the region. With rather strong low-level and deep-layer shear generally forecast to overspread an increasingly moist but only weakly unstable environment, the strength of large-scale forcing will be crucial for determining the potential for organized deep convection. Given the unusually large uncertainty at this forecast range, and the likelihood for instability to remain quite weak even in the stronger scenarios, no probabilities have been included with this outlook. However, if guidance trends towards a more strongly forced scenario across this region, then severe probabilities may eventually be needed for Tuesday night into Wednesday morning. ...Dean.. 11/19/2023 $$ = = = 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) .