Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jul 11 2023 07:31:09 ACUS03 KWNS 110731 SWODY3 SPC AC 110729 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Tue Jul 11 2023 Valid 131200Z - 141200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS INTO PARTS OF THE MIDWEST...OH/TN VALLEYS...MID ATLANTIC...AND NORTHEAST... ....SUMMARY... Strong to potentially severe storms will be possible on Thursday from the central High Plains vicinity eastward into parts of the Midwest, Ohio and Tennessee Valleys, Mid Atlantic, and Northeast. ....Synopsis... Little change to the large-scale pattern is expected across the CONUS on Thursday. A deep upper-level cyclone will continue to meander near northern Manitoba/Ontario and Hudson Bay, while an upper ridge will persist over the Southwest. A broad region of northwesterly midlevel flow will be maintained from parts of the Great Plains into the Midwest/Ohio Valley. ....High Plains into the Midwest/Ohio Valley... Details of severe-thunderstorm potential on Thursday will be strongly influenced by antecedent convection on Tuesday/Wednesday, resulting in substantial uncertainty. In general, one or more storm clusters/remnant MCSs may be ongoing Thursday morning somewhere near the lower/mid MS Valley into parts of the OH/TN Valleys, which could pose a lingering severe threat early in the day. During the afternoon, moderate to strong instability will likely develop near/south of a convectively reinforced surface boundary draped somewhere from the central High Plains into parts of the MS/OH/TN Valleys. The potential overlap of instability and stronger deep-layer shear will be determined by how far south the effective front is pushed by prior convection, but there will be some potential for organized storm development during the afternoon/evening near the front, and potentially within a post-frontal regime across the central High Plains. The details of storm mode and potential MCS development remain unclear, but some threat for strong/damaging gusts and some hail may evolve across a broad region from eastern CO into the central Plains, Midwest, and OH/TN Valleys. ....Mid Atlantic/Northeast... A cold front that will move into parts of New England on D2/Wednesday may lift northward as a warm front on Thursday, as multiple embedded shortwave troughs and potentially a weak surface low/trough move from the upper Great Lakes region into the Northeast. Scattered diurnal thunderstorm development will be possible within a rather moist environment, with deep-layer shear becoming marginally favorable for organized convection. Storm intensity may be somewhat limited by weak midlevel lapse rates, but the strongest cells/clusters may be capable of locally damaging gusts and possibly a tornado. ...Dean.. 07/11/2023 $$ = = = 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) .