Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Mar 24 2023 17:30:33 ACUS02 KWNS 241730 SWODY2 SPC AC 241728 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Fri Mar 24 2023 Valid 251200Z - 261200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHEAST AND UPPER OHIO VALLEY... ....SUMMARY... Isolated strong to severe thunderstorms appear possible from the Florida Panhandle northeastward into South Carolina on Saturday. Other convection capable of producing isolated severe wind gusts may occur across parts of the upper Ohio Valley and vicinity. ....Synopsis... A large-scale upper trough will continue to eject northeastward from the MS Valley across much of the eastern CONUS on Saturday. Very strong low/mid-level flow fields associated with this upper trough will overspread the OH Valley and Mid-Atlantic. A deep surface low will also develop northeastward over the Great Lakes and into southern Ontario through Saturday evening. A cold front will sweep east-southeastward over much of the eastern states, with the trailing portion of this front stalling over the Southeast. ....Southeast... A line of thunderstorms should be ongoing Saturday morning across parts of upstate SC into GA and southeast AL. This line will probably decay through the morning hours, but may still pose an isolated threat for damaging winds. Although the better forcing associated with the upper trough will remain generally displaced to the north of this region, sufficient instability and shear are forecast to support some severe threat ahead of the cold front. Primary uncertainty remains overall thunderstorm coverage given the nebulous forcing. Most 12Z runs of convection-allowing guidance show some increase in thunderstorm coverage and intensity Saturday afternoon, either with the leading line of convection, and/or along the synoptic cold front. Deep-layer shear will remain strong enough for supercells, with associated threat for large hail and gusty/damaging winds. A tornado or two may also occur, even though low-level flow is expected to gradually veer/weaken through the day. Given the continued uncertainty regarding how many robust thunderstorms may develop, have maintained the Marginal Risk across parts of the Southeast, with some expansion. ....Eastern Ohio into Western Pennsylvania and Northern West Virginia... Low-level moisture should remain quite limited across the upper OH Valley vicinity on Saturday. But, even modest daytime heating of the airmass ahead of the cold front may support weak surface-based instability given rapidly cooling mid-level temperatures associated with the ejecting upper trough. Low/mid-level flow will likely be quite strong across OH into PA and vicinity Saturday afternoon. There appears to be potential for isolated, low-topped convection to occur along or just ahead of the cold front around peak afternoon heating. If this activity develops, then some threat for severe/damaging winds should exist given the strength of the low-level flow forecast. ...Gleason.. 03/24/2023 $$ = = = 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) .