Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Aug 16 2024 07:13:57 ACUS03 KWNS 160713 SWODY3 SPC AC 160713 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0213 AM CDT Fri Aug 16 2024 Valid 181200Z - 191200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE MID-ATLANTIC AND CAROLINAS WEST-SOUTHWESTWARD INTO THE SOUTHEAST...AND ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ....SUMMARY... A marginal severe threat is expected on Sunday from the Mid-Atlantic and Carolinas west-southwestward into much of the Southeast. A marginal severe threat will also be possible across parts of the central and northern High Plains. ....Mid-Atlantic/Carolinas/Southeast... An upper-level trough is forecast to move eastward into the southern and central Appalachians on Sunday. At the surface, an associated cold front is forecast to advance eastward into the Atlantic Coastal Plains, and southeastward into the southeastern states. Ahead of the front, surface dewpoints are expected to be in the 70s F, which will contribute to moderate instability across a broad area by afternoon. Isolated to scattered thunderstorms are expected to form near the boundary. Some convection may also develop southeastward into the moist airmass. Although the upper-level trough will likely provide some support for convective development, the area ahead of the trough from the Mid-Atlantic southeastward into the eastern Gulf Coast states is forecast to have marginal deep-layer shear for severe storms. A few isolated severe gusts will be possible near and after peak heating, mainly as low-level lapse rates become steep in the late afternoon. Further west into the lower Mississippi Valley, moderate instability is expected to develop by afternoon. Mid-level flow behind the trough will be northwesterly. This will result in stronger deep-layer shear, which should be sufficient for an isolated severe threat. The main uncertainty on Sunday in the lower Mississippi Valley is how instability will be distributed by afternoon. Some model solutions suggest that a cluster of storms will develop early in the day, which could negatively impact instability across parts of the region. Areas that can avoid this negative impact could have potential for severe wind gusts and hail during the afternoon. ....Central and Northern High Plains. An upper-level ridge is forecast to remain over the High Plains on Sunday. Beneath the ridge, a somewhat moist airmass should be in place with surface dewpoints mostly in the 50s and 60s F. As surface temperature warm on Sunday, isolated thunderstorm development will be possible across much of the central High Plains. Forecast soundings Sunday afternoon from eastern Colorado northward into western South Dakota have steep low-level lapse rates and moderate deep-layer shear. This suggest an isolated severe threat will be possible. However, subsidence associated with the ridge will negatively impact convective development, and any severe threat should remain marginal. ...Broyles.. 08/16/2024 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .