Subj : DAY48SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Feb 29 2024 09:48:27 ACUS48 KWNS 290948 SWOD48 SPC AC 290946 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0346 AM CST Thu Feb 29 2024 Valid 031200Z - 081200Z ....DISCUSSION... An upper trough over the western U.S. early on Day 4/Sun will lift northeast toward the Upper Midwest by early Day 5/Mon. A deep surface low over the norther Plains will lift northeast at the same time. Meanwhile a cold front attendant to the low will push east across the Mid-MO and Upper MS Valley. Southerly low-level flow will allow for Gulf moisture to return northward ahead of the front. However, 60s F surface dewpoints (and better thermodynamics) will remain well south of better large-scale ascent and vertical shear associated with the trough and cold front, limiting severe potential. On Day 5/Mon, the upper trough will continue to shift east/northeast across the north-central U.S. Meanwhile, a shortwave impulse embedded within westerly southern stream flow will move across northern Mexico and south TX and the western Gulf vicinity. This will result in increasing west/southwesterly flow aloft as deeper Gulf moisture spreads across south and east TX into the Lower MS Valley during the afternoon and into the overnight hours. However, poor lapse rates are forecast and large-scale ascent will remain modest. Additionally, flow through around 700 mb will remain somewhat weak, leading to marginal vertical shear. While some strong or severe thunderstorms could develop across the warm sector ahead of a southeastward-advancing cold front during the afternoon/evening from east TX into the Lower MS Valley, potential appears to low to introduce 15 percent probabilities at this time. Model spread increases during the Days 6-8/Tue-Thu time frame. However, it appears a stronger southern stream jet may develop and move toward south-central portions of the U.S., though predictability is low. ...Leitman.. 02/29/2024 = = = 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) .