Subj : DAY48SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon May 01 2023 09:00:13 ACUS48 KWNS 010900 SWOD48 SPC AC 010858 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Mon May 01 2023 Valid 041200Z - 091200Z ....DISCUSSION... ....D4/Thursday: Southern/central Plains... A mid/upper-level shortwave trough is forecast to move across parts of the southern Plains on Thursday. This wave will likely deamplify as it crests a shortwave ridge, but moderate mid/upper-level flow is expected to overspread an increasingly moist and unstable airmass across the southern Plains during the afternoon. Scattered thunderstorm development is expected along the dryline, with moderate buoyancy and increasingly favorable deep-layer shear supporting the potential for organized clusters and a few supercells, with an attendant threat of large hail and localized severe gusts. A 15% area has been added where confidence is currently greatest in organized convection during the late afternoon and early evening, with some future adjustments likely based on dryline position and northern extent of stronger deep-layer flow/shear. ....D5/Friday and beyond... Predictability begins to wane as soon as D5/Friday with regard to organized severe-thunderstorm potential. The mid/upper-level low that will persist near the Pacific Coast for much of the week is forecast to begin ejecting northeastward on Thursday, weakening as it does so. The remnant mid/upper-level trough will then gradually move across parts of the Great Plains, though there is considerable spread regarding the timing, location, and intensity of this trough into the coming weekend. There will be some potential for stronger mid/upper-level flow and favorable deep-layer shear to impinge upon an expanding reservoir of moderate to locally strong buoyancy across the central/southern Plains into the lower/mid MS Valley, but details regarding the severe-thunderstorm threat on any particular day remain very uncertain at this time. ...Dean.. 05/01/2023 = = = 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) .