Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Feb 02 2024 05:35:36 ACUS01 KWNS 020535 SWODY1 SPC AC 020534 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1134 PM CST Thu Feb 01 2024 Valid 021200Z - 031200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN GREAT PLAINS... ....SUMMARY... Isolated to scattered severe thunderstorms will be possible beginning late afternoon Friday across parts of the southern Great Plains. ....Southern Great Plains... Late-evening satellite imagery suggests a strong southern-stream short-wave trough is noted over southern CA/Baja Peninsula. This feature is ejecting east in line with latest model guidance, and should approach west TX by late afternoon. While the primary trough will only advance into the TX south Plains by the end of the period, deep-layer ascent and strong shear will overspread the southern Plains as 12hr midlevel height falls, on the order of 90m, evolve across this region. Boundary-layer moistening has permitted 50s surface dew points to return across much of TX east of a line from Sanderson-SJT-ABI-Vernon, even advancing into portions of OK as of 05z. Lee surface trough/dryline will hold near this position as modest boundary-layer heating is expected across the southern High Plains by mid afternoon. While lee cyclogenesis is not expected to be that significant, low-level convergence will prove more than adequate for deep convection by late afternoon as substantial midlevel cooling will overspread the dryline. Latest data suggests 500mb temperatures should cool to near -18C by peak heating and low-level lapse rates west of the boundary will be substantially steep, enough for surface-based parcels to convect. NAM forecast sounding at 21z for AMA exhibits SBCAPE on the order of 600 J/kg within a sheared environment favorable for organized updrafts. HREF supports the idea of forced convection evolving across this portion of the High Plains with subsequent upscale growth/movement into western OK by early evening. Scattered convection is also expected south along/ahead of the dryline as profiles adjust within a very diffluent high-level flow regime. Buoyancy will be greater at lower latitudes, especially south of I20, and forecast soundings favor potential supercells and large hail. While initial activity may be somewhat discrete, this strongly dynamic system should encourage a more linear mode of convection by mid evening. An elongated QLCS will surge across the southern Plains during the overnight hours. While hail is the primary severe threat early, especially near the initiating corridor, locally strong winds, and perhaps a brief tornado are the threats downstream. ...Darrow/Squitieri.. 02/02/2024 $$ = = = 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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .