Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jan 18 2023 12:53:40 ACUS01 KWNS 181253 SWODY1 SPC AC 181251 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0651 AM CST Wed Jan 18 2023 Valid 181300Z - 191200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS STARTING TODAY IN EAST TX AND CONTINUING ACROSS THE ARK-LA-MISS TO THE LOWER OH VALLEY THROUGH EARLY TONIGHT... ....SUMMARY... Severe thunderstorms are possible from far east Texas today across the Ark-La-Miss to the lower Ohio Valley through early tonight. ....Ark-La-Miss and vicinity through early tonight... In advance of a midlevel trough ejecting northeastward from the southern Rockies toward the central Plains, a surface cyclone will likewise develop northeastward from northern OK this morning to southeast KS this afternoon and northern MO overnight. South of the cyclone track, a remnant lee trough/Pacific cold front will translate into far eastern OK/TX by late afternoon, as a warm front moves northward across the Ark-La-Miss to the lower OH Valley by early tonight. The warm sector will be characterized by mid-upper 60s dewpoints, and some modest surface heating in cloud breaks. Lapse rates will not be particularly steep, and increasingly moist profiles (as ascent increases from the west) will tend to limit warm sector buoyancy (MLCAPE 500-1000 J/kg). It appears that slightly elevated convection, forming this morning in the warm advection zone over northeast TX, will expand in coverage and spread northeastward through the day, along and just east of the surface trough/front. Vertical shear profiles/hodographs will be favorable for supercells and some tornado threat, though the thermodynamic profiles cast some doubt on the extent of supercell development. Thus, will maintain a conditional threat for a couple of tornadoes and damaging winds through late evening, as storms gradually evolve into a line along or just ahead of the primary wind shift. The eastern extent of any severe threat later tonight will be limited poor lapse rates and minimal buoyancy. ....Southeast KS this afternoon... As the midlevel trough and surface cyclone move northeastward into KS this afternoon, the system will trend more toward an occluded structure. In the wake of morning rainfall, there will be a small window of opportunity for surface heating/steepening low-level lapse rates near and east-southeast of the surface cyclone, beneath the midlevel dry slot. Buoyancy will be weak (SBCAPE up to 500 J/kg), but could become sufficient for a low-topped supercell or two from about 20-23z. Isolated large hail and perhaps a brief/weak tornado will be possible. ...Thompson/Dean.. 01/18/2023 $$ = = = 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) .