Subj : DAY48SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Mar 08 2025 09:21:48 ACUS48 KWNS 080921 SWOD48 SPC AC 080919 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0319 AM CST Sat Mar 08 2025 Valid 111200Z - 161200Z ....DISCUSSION... ....Day 5/Wed - ArkLaTex Vicinity... Severe thunderstorm potential may increase around Day 5/Wednesday as a shortwave upper trough over the Southwest and northern Mexico develops east into the southern Plains. The GFS model suite is much more aggressive in the strength of this system compared to the ECMWF, with the GFS depicting a negative-tilt trough with a southwesterly jet streak overspreading the ArkLaTex vicinity Wednesday evening. The ECMWF on the other hand depicts a positive-tilt upper trough located further south, and with model soundings depict stronger capping. While some northward moisture return from the western Gulf is likely to occur across east TX and the ArkLaTex vicinity, large spread in surface features also is apparent. Severe probabilities may be needed at some point across the region, but uncertainty is still too high to delineate unconditional 15 percent severe probabilities. ....Day 7-8/Fri-Sat - Mid/Lower MS Valley into the Southeast... Low predictability due to large spread continues in medium-range guidance for the end of the period. However, forecast guidance generally depicts a strong springtime large-scale upper trough ejecting across the Plains into the eastern U.S. late in the period. This strong upper-level trough will result in a deepening surface cyclone over the Plains moving east/northeast into some portion of the Midwest, allowing Gulf moisture to spread northward centered roughly on the Mid/Lower MS Valley (Fri) into the Southeast (Sat). Given large model disparity in the placement and timing of key features, confidence/predictability is too low to delineate severe probabilities at this time, but outlook areas will likely be needed in subsequent outlooks anywhere from the ArkLaTex and Deep South into the Midwest. ...Leitman.. 03/08/2025 = = = 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) .