Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Aug 14 2024 07:29:40 ACUS03 KWNS 140729 SWODY3 SPC AC 140728 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CDT Wed Aug 14 2024 Valid 161200Z - 171200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE GREAT LAKES INTO THE OHIO/TENNESSEE VALLEYS AND MID-SOUTH... ....SUMMARY... At least isolated strong to severe thunderstorms may develop Friday over portions of the Great Lakes into the Ohio/Tennessee Valleys and Mid-South. ....Great Lakes into the Ohio/Tennessee Valleys and Mid-South... As upper ridging remains suppressed across parts of the Southwest and southern Plains, an upper trough should continue to progress slowly eastward over portions of the Great Lakes/Midwest and OH Valley on Friday. A belt of enhanced mid-level flow should be present over parts of the mid MS Valley into the OH Valley, and related deep-layer shear should be sufficient for some updraft organization with thunderstorms that can develop through the period. A weak/occluded surface low beneath the upper cyclone should likewise develop slowly eastward over the Great Lakes and southern Ontario. An ill-defined front/wind shift is forecast to extend south-southwestward from this surface low. Thunderstorms will probably be ongoing Friday morning over parts of the OH Valley. This activity is generally expected to remain sub-severe and further weaken through the morning/early afternoon as it moves eastward into a less unstable airmass. Some recovery is expected to the west of the early-day convection and ahead of the weak front, with a rather moist low-level airmass forecast to be in place from portions of the lower OH Valley into the TN Valley and Mid-South vicinity. While deep-layer shear is forecast to gradually weaken with southward extent, a broad area of at least moderate instability should develop in tandem with daytime heating along and east/southeast of the front. Any thunderstorms that do develop could become strong to severe with mainly a hail/wind threat given the forecast environment, but considerable uncertainty remains concerning details of convective initiation and development. Only weak low-level convergence along the surface front also lends uncertainty in where greater severe thunderstorm coverage may occur. Therefore, for now have included a broad Marginal Risk for Friday. But, higher severe probabilities may eventually be needed if confidence increases in an MCS/cluster occurring. ...Gleason.. 08/14/2024 $$ = = = 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) .