Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Dec 13 2022 17:32:05 ACUS02 KWNS 131731 SWODY2 SPC AC 131730 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CST Tue Dec 13 2022 Valid 141200Z - 151200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN LOUISIANA...SOUTHERN/CENTRAL MISSISSIPPI...SOUTHERN ALABAMA...AND THE WESTERN FLORIDA PANHANDLE... ....SUMMARY... Tornadoes and damaging winds are expected Wednesday over parts of southern Louisiana, southern/central Mississippi, southern Alabama and the western Florida Panhandle. A few strong tornadoes may occur. ....Lower Mississippi Valley into the Southeast... A large upper cyclone will encompass much of the central CONUS on Wednesday, with a rather strong mid-level jet expected to overspread much of the lower/mid MS Valley and the Southeast through the period. An embedded mid-level perturbation is forecast to advance across the southern Plains to the lower MS Valley/Mid-South by Wednesday evening. This feature should encourage a weak surface low to develop northeastward from coastal southern LA to western TN/KY in the same time frame. Rich low-level moisture will attempt to return northward through the day across the central Gulf Coast states ahead of a cold front, but persistent surface ridging should hinder the northward advance of the related surface warm front across central AL/GA. A broken line of thunderstorms will likely be ongoing at the start of the period Wednesday morning across parts of southern LA into southern/central MS in association with strong low-level warm advection. A threat for tornadoes and damaging winds should continue with this activity Wednesday morning, as embedded supercells encounter increasing low-level moisture and instability as filtered diurnal heating occurs. The thermodynamic environment across this region should gradually improve through the day, with MLCAPE perhaps reaching as high as 1000-1500 J/kg in a narrow zone ahead of the morning activity. Current expectations are for convection to gradually increase in coverage and intensity Wednesday afternoon from southeastern LA into southern MS. Deep-layer shear will be more than strong enough to support supercells, and a strengthening south-southwesterly low-level jet will aid updraft rotation as effective SRH increases and hodographs become enlarged. The threat for tornadoes will likely increase across this region as well Wednesday afternoon and evening, especially if convection can remain somewhat discrete ahead of the eastward-advancing cold front. A few strong tornadoes appear possible given the strength of the low-level flow, and as near surface winds potentially back to south-southeasterly as the surface low develops across MS. Any outflow boundary from the morning convection may serve to focus this strong tornado potential. Otherwise, scattered damaging winds and isolated large hail will also be a possibility as thunderstorms spread eastward across southern AL and the FL Panhandle Wednesday evening/night. The tornado threat will likely continue eastward across these areas as well, with both strong low-level and deep-layer shear present to organize updrafts. ...Gleason.. 12/13/2022 $$ = = = 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) .