Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Feb 28 2023 06:45:31 ACUS02 KWNS 280645 SWODY2 SPC AC 280644 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CST Tue Feb 28 2023 Valid 011200Z - 021200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTHEAST TX...SOUTHERN/CENTRAL AR...NORTHERN LA...NORTHERN MS...SOUTHWEST TN... ....SUMMARY... Severe thunderstorms will be possible on Wednesday from northeast Texas to the Lower Mississippi Valley, with a threat of hail, damaging wind, and a couple of tornadoes. ....Synopsis... A deep upper-level trough is forecast to amplify and dig southeastward on Wednesday, moving from the Great Basin towards the southern Rockies by Thursday morning. As this occurs, a surface low is forecast to begin deepening in the lee of the southern Rockies by late in the period. A broad region of moderate to strong southwesterly midlevel flow is expected downstream of this deep upper trough, with a low-amplitude shortwave forecast to move across the Great Lakes and Ohio Valley regions through the day/evening, in conjunction with a weak surface low and cold front. Low-level southerly flow will support continued moisture return from central/east TX eastward into parts of the lower MS Valley and Southeast. ....Northeast TX into the lower MS Valley and TN Valley regions... The details remain uncertain, but one or more rounds of convection appear possible Wednesday into Wednesday night from northeast TX into the lower MS Valley and TN Valley, within a conditionally favorable severe-thunderstorm environment. Increasing low-level moisture, beneath relatively steep midlevel lapse rates, will support the potential for thunderstorm development along the northern periphery of the deeper moisture plume from northeast TX into parts of AR/northern LA and potentially extending into the Mid South vicinity. Initially elevated storms will be possible during the morning, with an increasing potential for surface-based convection by afternoon/evening. Moderate buoyancy (MLCAPE in excess of 1000 J/kg) and strong effective shear (generally 50+ kt) will support the potential for organized storms, though storm coverage and mode remain uncertain, due to the expected subtle forcing for ascent. A couple of organized cells/clusters may evolve during the afternoon/evening, with a threat of damaging winds and hail. If any supercells can be sustained, then modest (but sufficient) low-level shear/SRH will support the potential for a couple of tornadoes as well. A Slight Risk has been added from northeast TX into parts of AR and northern MS, where the greatest storm coverage is expected at this time. ....Parts of the OH Valley... Isolated to widely scattered thunderstorm development appears possible along the weak cold front Wednesday afternoon/evening across portions of the OH Valley. Guidance varies regarding the extent of low-level moistening and destabilization, though a couple of organized storms cannot be ruled out, given rather strong deep-layer flow/shear across the region. Depending on model trends regarding destabilization and storm coverage, severe probabilities may eventually need to be extended northward into this region. ...Dean.. 02/28/2023 $$ = = = 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) .