Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jan 11 2023 17:26:48 ACUS02 KWNS 111726 SWODY2 SPC AC 111725 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CST Wed Jan 11 2023 Valid 121200Z - 131200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE OHIO VALLEY SOUTHWARD ACROSS THE MID SOUTH AND PARTS OF THE SOUTHEAST... ....SUMMARY... Isolated to scattered severe thunderstorms appear possible Thursday across parts of the Tennessee/Ohio Valleys, and the Southeast. Damaging winds should be the main threat, but a brief tornado or two may also occur. ....Synopsis... A strengthening upper trough is forecast to move eastward across the eastern half of the U.S. Thursday. By the end of the period, a highly amplified flow field aloft will prevail over the U.S., with a Pacific trough approaching the West Coast, a ridge across the Intermountain West and Canadian Rockies, and a trough over the East. At the surface, a low initially progged to reside near the confluence of the Ohio and Mississippi Rivers will deepen steadily as it shifts northeastward, reaching the Pennsylvania/New York vicinity late. South of the low, a trailing cold front will cross the Mid South and central Gulf Coast states through the day, reaching the Appalachians during the evening. Overnight, the front will continue making steady eastward progress, likely reaching the Atlantic Coast near the end of the period. ....Ohio and Tennessee Valleys into the Southeast... Showers and scattered thunderstorms should be ongoing at the start of the period, ahead of the advancing cold front, from the middle Mississippi/lower Ohio Valleys southward into the central Gulf Coast states. While instability should remain limited overall, due to return of an incompletely modified Gulf boundary layer and substantial cloud cover, storms should nonetheless increase gradually in coverage through the day as a subtle increase in warm-sector CAPE occurs. Given antecedent stability, and a low-level capping inversion, ascent near the front will likely be required to eliminate the inversion and permit storm development -- which suggests largely linear storm mode. Still, with deep-layer flow veering modestly and speed increasing substantially with height, organized updrafts along with locally rotating elements within the line are expected. Damaging winds will likely be the primary risk, likely peaking through the afternoon and then very gradually diminishing during the evening -- in part due to a less favorable thermodynamic environment expected to persist east of the southern Appalachians. A couple of tornadoes will also be possible, across a broad area -- mainly of the brief variety within the linear band of convection. Severe risk will likely decrease more substantially overnight, as frontal convection nears -- and eventually clears -- the Atlantic coast. Convection lingering across Florida as the front slides southward across the Peninsula overnight should remain sub-severe. ...Goss.. 01/11/2023 $$ = = = 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) .