Subj : DAY48SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Feb 11 2023 08:31:58 ACUS48 KWNS 110831 SWOD48 SPC AC 110830 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CST Sat Feb 11 2023 Valid 141200Z - 191200Z ....DISCUSSION... A potent mid-level shortwave trough is forecast to quickly move from the southern Great Plains northeastward into the Upper Midwest/Great Lakes and weaken on Tuesday into Tuesday night (day 4). Relatively limited moisture return is expected across the Arklatex into the lower MS Valley as the disturbance becomes increasingly displaced from the northwest Gulf Coast. Some risk for isolated severe thunderstorms may occur in the warm sector, but a 15% severe threat is not warranted at this time. The focus for severe is overwhelmingly concentrated on Wednesday through Thursday across parts of the southern Great Plains eastward into the MS/OH/TN Valleys. Model guidance continues to show a very powerful upper-level system ejecting into the southern Great Plains on Tuesday from the Desert Southwest. Additional modification of the airmass across the northwest Gulf Coast will aid in severe-thunderstorm potential. Surface dewpoints will probably reach the lower-mid 60s in the Arklatex on Wednesday into Wednesday night. Model variability and greater confidence and a farther-west edge of low-level moisture/surface low placement in the southern Great Plains necessitated a shift of the severe probabilities west on Wednesday (day 5). Once model spread is reduced, a 30-percent severe area will likely be introduced. A continuation of thunderstorm activity will likely occur into Thursday as the warm sector potentially develops as far north as the OH Valley. Have expanded the severe risk as there is now greater confidence in the forecast surface-low track on Thursday being across parts of the Midwest. Model spread increases by late in the extended period before severe potential likely becomes very low next weekend. ...Smith.. 02/11/2023 = = = 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) .