Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Feb 25 2023 12:47:11 ACUS01 KWNS 251247 SWODY1 SPC AC 251245 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0645 AM CST Sat Feb 25 2023 Valid 251300Z - 261200Z ....NO SEVERE THUNDERSTORM AREAS FORECAST... ....SUMMARY... Isolated thunderstorms will be possible over parts of the Tennessee Valley to southwestern Virginia, along the coast of southern California, and from northeast Oklahoma and southeastern Kansas into the Ozarks. ....Synopsis/Discussion... The main mid/upper-level influence on this forecast will be a pronounced cyclone -- evident in moisture-channel imagery over much of coastal CA, with a center offshore, approximately 200 nm west of SBA. The cyclone will turn eastward today, moving ashore with its center around SBA by 00Z. Until the midlevel low and associated troughing pass, accompanying large-scale ascent/cooling will steepen low/middle-level lapse rates atop a moist boundary layer near the coast, supporting isolated thunder potential. The associated low- level frontal zone should contribute enough forcing for a band of precip and embedded/shallow convection to develop and move across portions of AZ late tonight. However, forecast soundings suggest insufficiently large/deep buoyancy for an areal lightning threat, precluding a general thunderstorm area at this time. Strong gusts are possible with this activity, as well as in localized, terrain- enhanced, nonconvective gradient winds nearby. By 12Z, the 500-mb low should be near LAS, with a sharp, basal shortwave trough moving through the southern semicircle of the cyclone, across northern Baja and southeastern CA. The downstream ridge will have shifted eastward to a position from the central Gulf across eastern OK, central NE, and eastern MT. Near and just downstream from that ridge, warm advection and leading-stage return flow above the surface is fostering isolated, elevated, shallow thunderstorms from the middle TN region east-northeastward toward the TRI area, and may support another round of isolated, non-severe thunderstorms across northeastern OK into the Ozarks late overnight. ...Edwards/Kerr.. 02/25/2023 $$ = = = 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) .