Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jan 12 2023 05:43:20 ACUS01 KWNS 120543 SWODY1 SPC AC 120541 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1141 PM CST Wed Jan 11 2023 Valid 121200Z - 131200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL AND EASTERN ALABAMA INTO CENTRAL AND NORTHERN GEORGIA... ....SUMMARY... Severe thunderstorms are expected today across portions of the Tennessee Valley into the Southeast. Several damaging wind gusts are likely, though occasional bouts of large hail and at least a few tornadoes are also possible. ....Synopsis... A positively tilted mid-level trough and associated surface low will traverse the OH/TN Valley areas today as a surface cold front sweeps across the Southeast. Low-level moisture will stream north from the Gulf of Mexico ahead of the advancing front. The moisture will be overspread by a seasonably strong low-level jet and cold temperatures aloft, providing enough buoyancy, shear, and deep-layer ascent to support a threat for several strong to potentially severe thunderstorms, especially from the TN Valley into the Southeast this afternoon into the evening hours. ....TN Valley into the Southeast... Scattered strong to potentially severe thunderstorms should be ongoing at the beginning of the period across the TN Valley ahead of the surface low. These storms should be fueled by at least some elevated instability, with strong deep-layer shear and 7-8 C/km mid-level lapse rates promoting an isolated large hail threat in association with transient supercell structures. With diurnal heating, strong thunderstorms should continue to develop along the cold front in MS by morning and progress eastward through the afternoon. The 00Z LIX observed sounding shows mid 60s F surface dewpoints and near 8 C/km mid-level lapse rates. These steeper lapse rates should continue to overspread the Gulf Coast states given strong westerly 700-500 mb flow. Low-level moisture should remain modest (i.e. low 60s F surface dewpoints), but the steeper lapse rates should compensate to support 500-1000 J/kg of skinny MLCAPE. A 40-50 kt low-level jet overspread by even stronger westerlies aloft should result in elongated hodographs, with some curvature in the surface-3 km layer. As such, a mix of line-embedded transient supercells and bowing segments are expected along the front. Modestly dry 850-500 mb air may promote efficient downward momentum transport through the strong low-level jet to promote a damaging/severe wind gust threat, hence the Category 3/Enhanced risk across central AL/GA. Large hail may initially accompany the stronger, sustained updrafts given the steep mid-level lapse rates. Given the modest low-level moisture, the tornado threat appears a bit more conditional, though at least a few brief tornadoes may still develop in either embedded QLCS circulations, or any discrete, sustained storms ahead of the line. ...Squitieri/Supinie.. 01/12/2023 $$ = = = 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) .