Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Apr 04 2023 07:31:00 ACUS03 KWNS 040730 SWODY3 SPC AC 040729 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Tue Apr 04 2023 Valid 061200Z - 071200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THURSDAY ACROSS PARTS OF THE MID ATLANTIC AND DEEP SOUTH TEXAS... ....SUMMARY... Strong thunderstorms posing at least some risk for severe weather are possible across parts of the Mid Atlantic and Deep South Texas Thursday. ....Synopsis... Within the main branch of split westerlies emanating from the Pacific, models indicate that a broad, occluded cyclone, initially centered near James Bay, will continue to weaken during this period. Renewed cyclogenesis may occur farther east, across northern Quebec through Newfoundland and Labrador, but it appears that this will remain modest in strength. The associated cold front trailing to the south is forecast to advance from the upper Ohio Valley and lee of the lower Great Lakes across much of the northern into middle Atlantic by late Thursday night, as the remnant mid-level troughing accelerates eastward and suppresses mid-level short wave ridging initially building across New England and the Canadian Maritimes. In lower latitudes, prominent mid-level ridging appears likely to be maintained, centered over the southeastern Gulf of Mexico and Florida Peninsula, and a considerable influence across much of the Southeast. Beneath its northwestern periphery, the trailing flank of the cold front is expected to weaken while slowly advancing across the northwestern Gulf coast vicinity. However, seasonably moist return flow will persist along/above it, downstream of low amplitude mid-level troughing across the subtropical eastern Pacific into the northern Mexican Plateau. ....Mid Atlantic... Preceding the cold front, models continue indicate that low-level moisture return coupled with daytime heating will support modest destabilization east of the Allegheny Mountains by Thursday afternoon. Scattered storms probably will initiate along the higher terrain, with at least deep-layer shear conducive to supercells structures posing a risk for severe wind and hail. Tornado potential remains a bit more uncertain. Storms are likely to gradually spread off the higher terrain with the mid-level height falls, and they could eventually consolidate into an organizing line or cluster overspreading coastal areas with potential for damaging wind gusts. It does not appear out of the question that severe weather probabilties could be increased further in later outlooks for this period. ....Lower Rio Grande vicinity/Deep South Texas... NAM forecast soundings for Thursday exhibit "loaded gun" type structure, with a deep moist layer surmounted by at least modestly steep lapse rates, above the shallow cold front. It appears possible that forcing for ascent, associated with a weak perturbation emanating from the upstream troughing, will aid isolated intense convection capable of producing large hail. ...Kerr.. 04/04/2023 $$ = = = 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) .