Subj : DAY48SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Nov 11 2024 09:58:32 ACUS48 KWNS 110958 SWOD48 SPC AC 110956 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0356 AM CST Mon Nov 11 2024 Valid 141200Z - 191200Z ....DISCUSSION... A shortwave trough should exit the Lower to Mid-Atlantic Coast on D4/Thursday, with amplification discrepancies from D3 persisting. The 00Z ECMWF appears to be the remaining holdout of the deterministic guidance for a low-probability severe threat in the northeast Gulf Coast vicinity. Still, even it suggests low-level flow should both decrease and become veered through the day, where rich low-level moisture exists. Instability appears likely to be meager and overall severe potential appears low. The next broad mid/upper trough should progress into the West by D5/Friday. Guidance appears to be coalescing towards two distinct shortwave impulses evolving within this longwave pattern. The lead one is progged to track northeast into the northern Great Plains and then pivot east across the Upper Midwest/south-central Canada over the weekend. Meanwhile, a basal shortwave impulse should become established off the southern CA coast. This may gradually move east over the Desert Southwest and northwest Mexico late in the period. Guidance continues to differ with the degree of continental airmass intrusion into the northern Gulf, in the wake of the shortwave trough departing the East on D4. Overall trends and likelihood of surface ridging persisting across parts of the Gulf Coast suggest that returning moisture will probably be of low quality in advance of the north-central states wave. However, this may yield multiple days of return flow and an increasingly moist warm sector becoming established over the southern Great Plains by D8/Monday. SPC GEFS-based ML guidance has trended down to a 2 percent probability for D6/Saturday, after depicting a 15 percent area yesterday. It has instead, increased probabilities to 15 percent on D7/Sunday. Meanwhile, NSSL GEFS-based ML guidance has decreased probabilities for D7 from 10 percent yesterday to 5 percent today. Both of these are 5 percent or less on D8, when the ECMWF ensemble mean would be more indicative of 15 percent potential. Given the lack of consistency, a severe weather highlight for D7 or D8 appears premature but bears watching in later cycles. ...Grams.. 11/11/2024 = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .