Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Feb 14 2023 06:55:39 ACUS02 KWNS 140655 SWODY2 SPC AC 140654 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CST Tue Feb 14 2023 Valid 151200Z - 161200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF TEXAS AND OKLAHOMA EASTWARD INTO THE LOWER MISSISSIPPI VALLEY AND LOWER OHIO VALLEY... ....SUMMARY... Widely scattered severe thunderstorms are possible over parts of Texas and Oklahoma beginning Wednesday during the late afternoon and evening. A severe threat will also develop east and include the lower Mississippi Valley Wednesday evening and into the overnight, while also developing into parts of the lower Ohio Valley. ....Synopsis... A somewhat complex, multi-modal severe episode is forecast from parts of OK/TX eastward through parts of the Mid South and into the lower MS/OH Valleys. A potent mid-level low and associated trough over the Desert Southwest will move east into the central US while the trough acquires a positive tilt. A trailing surface front from a Great Lakes cyclone will extend southwestward through the Ozarks and into the southern High Plains early Wednesday morning. A surface low is forecast to develop eastward along the boundary and reach central OK by early evening, and subsequently into southeast MO by daybreak Thursday. An arctic front will sweep southeast across OK and reach the TX coastal plain by the end of the period. ....TX/OK into the lower MS/OH Valleys... Southerly low-level flow will advect increasing moisture north into parts of TX/OK and the lower MS Valley during the day. The ECMWF/RAP/NAM are in general agreement in showing a surge of lower 60s deg F dewpoints into the Red River Valley by early Wednesday evening. Model guidance is suggesting isolated to scattered thunderstorms will develop by the early evening along the dryline near the Red River. Moderate buoyancy (1000-1500 J/kg MLCAPE) forecast over north TX and long hodographs (effective shear 65-70 kt) will favor supercells. Large to very large hail is possible with the more intense storms and potentially an isolated tornado risk. Some of this activity will likely move downstream into northeast TX/eastern OK and perhaps persist into portions of AR during the overnight, with the severe hazards largely governed by the convective mode. Farther east, a persistent low-level WAA corridor acting to advect moisture north will destabilize the airmass over the ArkLaMiss. By early evening, models indicate isolated to scattered thunderstorms developing on the nose of a strengthening south-southwesterly LLJ centered overhead. The LLJ is forecast to further intensify Wednesday night as it shifts northward into the lower TN/OH Valleys by early Thursday morning. Enlarged and elongated hodographs imply some of this evening/overnight activity to evolve into a cluster of supercells. A supercell-tornado risk may develop along with other severe hazards possible. Eventual storm mergers and additional storm development will favor a severe risk developing into the lower OH Valley late overnight, as moisture advects north through the MS Valley as the exit region of the LLJ focuses over the region. Farther south into parts of east TX/western LA, strengthening large-scale ascent will likely promote scattered thunderstorms. A risk for damaging gusts and perhaps a tornado may accompany this activity during the overnight. ...Smith.. 02/14/2023 $$ = = = 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) .