Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jan 18 2023 20:02:11 ACUS01 KWNS 182002 SWODY1 SPC AC 182000 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Wed Jan 18 2023 Valid 182000Z - 191200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE LOWER SABINE VALLEY AND THE LOWER MISSISSIPPI AND LOWER OHIO VALLEYS... ....SUMMARY... A few tornadoes and scattered damaging winds remain possible this afternoon from the Sabine Valley to the Mid-South, with more isolated coverage continuing into this evening across the Lower Ohio and Mississippi Valleys. ....Discussion... The only notable change this forecast update is to remove severe probabilities over the Arklatex in tandem with the eastward progression of the convective band. ...Smith.. 01/18/2023 ..PREV DISCUSSION... /ISSUED 1030 AM CST Wed Jan 18 2023/ ....Sabine and Lower MS/OH Valleys... Minimal change apparent for this outlook with a broken band of thunderstorms within the warm conveyor ahead of the eastern-moving cold front. The severe threat will likely peak this afternoon from the Sabine Valley into the Mid-South where 60s surface dew points (increasing to the southwest) supports MLCAPE of 500-1000 J/kg. The orientation and track of the shortwave trough over the central Great Plains suggests that mid-level lapse rates will weaken this afternoon, along with increasingly veered low-level flow diminishing hodograph curvature over the southern portion of the convective threat in TX/LA. This will likely maintain STP values in the 1-2 range this afternoon before diminishing later. A few tornadoes appear possible, with the damaging wind threat increasing some as the broken line consolidates into a broader QLCS. Confidence is decreasing with the longevity of an appreciable tornado and wind threat being maintained this evening. Bulk of morning CAM and machine-learning guidance are insistent on diminishing convective intensity towards 00Z, despite strengthening of the south-southwesterly low-level jet. Surface-based instability should eventually become pinched off in the Mid-South through eastern MS after sunset. This setup appears likely to yield a decreasing, but still a persistent low probability wind/brief tornado threat lingering tonight. ....Southeast KS... As the shortwave trough moves east across KS, a small corridor of opportunity for surface heating and steepening low-level lapse rates is possible near and east-southeast of the associated surface cyclone, beneath the mid-level dry slot. In the wake of morning rainfall, there may be scant MLCAPE approaching 250 J/kg. This could be barely adequate for a low-topped supercell with small to marginally severe hail and a brief weak tornado possible. $$ = = = 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) .