Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Mar 12 2025 19:28:21 ACUS03 KWNS 121928 SWODY3 SPC AC 121927 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Wed Mar 12 2025 Valid 141200Z - 151200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF THE MIDDLE TO LOWER MISSISSIPPI VALLEY...OHIO AND TENNESSEE VALLEYS... ....SUMMARY... A regional outbreak of severe storms is expected across much of the Mississippi Valley, eastward to the Lower Ohio and Tennessee Valleys late Friday afternoon into Saturday morning. Widespread damaging winds, several tornadoes, and hail will all be possible. ....Synopsis... An upper low associated with a powerful shortwave trough will deepen through the period, moving from NM at 12Z Friday to WI by 12Z Saturday. An associated intense midlevel speed max will pivot from OK at midday into the mid MS Valley by 00Z, then will lose intensity late as it approaches MI. Large-scale ascent will be maximized north of the midlevel jet roughly from the Ozarks and Ohio Valley northward. At the surface, low pressure (sub 980 mb) will deepen from KS into IA through evening, with a large expanse of southerly winds across the warm sector aiding northward moisture advection. Behind the primary wave, another system will be dig into northern MX and TX Saturday morning. This should maintain gradual height falls over the southeastern states through the period, despite being south of the initial system. ....Most of the area from the mid MO Valley into the TN Valley... A classic, progressive deep-layer cyclone will interact with a increasingly unstable air mass to produce widespread wind damage beginning near the KS/MO and OK/AR borders during early afternoon, and expanding northeast across much of MO, IA, IL, IN, western KY and parts of western TN through evening. Not only will extreme wind field favor damaging winds, but profiles will also favor supercells capable of fast-moving tornadoes, whether a broken line or in QLCS fashion along surging outflows. The steep lapse rates and rapid changes overall will also support strong tornado potential interspersed with the damaging wind area. Last, cells will also produce hail over northern areas where temperatures aloft are cold. ....MS/AL/TN Overnight... As the upper wave departs to the north, mid to perhaps upper 60s F dewpoints will surge north across MS, western AL and the western FL Panhandle during the evening and overnight. As mentioned, height falls will be maintained due to the secondary wave moving into TX. The result will be a persistent 50-60 kt low-level jet beneath 60 kt midlevel southwesterlies, and increasing boundary-layer moisture. This regime is likely to support scattered thunderstorms after 06Z, and the overall environment conditionally supports strong tornadoes. The severe risk will only increase into Saturday/D4. As such, have extended the Enhanced Risk farther south across MS and western AL. ...Jewell.. 03/12/2025 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .