Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jan 30 2024 12:43:22 ACUS01 KWNS 301243 SWODY1 SPC AC 301241 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0641 AM CST Tue Jan 30 2024 Valid 301300Z - 311200Z ....NO THUNDERSTORM AREAS FORECAST... ....SUMMARY... No thunderstorm areas are apparent through tonight. ....Synopsis/Discussion... In mid/upper levels, a high-amplitude yet progressive northern stream will dominate the synoptic-scale pattern across much of the CONUS, featuring troughing in the East, ridging over much of the West, and a northeastern Pacific cyclone staying offshore through this period. A strong, positively tilted trough -- apparent in moisture-channel imagery from northern ON across Upper MI, WI and IA -- will dig southeastward to the lower Ohio Valley and Mid-South region by 00Z, then reach the Carolinas and GA around 12Z tomorrow. This intensifying trough will be preceded by fairly extensive and strong plumes of vertical motion -- in the form of low-level warm-advection, closely followed by frontogenetic forcing and DCVA aloft. This will yield an area of precip overnight in parts of the southern Appalachians and Piedmont, spreading east to the coastal plain by the end of the period. Following a recent, strong, cold frontal passage, the low-level air mass will be too stable to support deep convection. Minute amounts of elevated, midlevel CAPE may develop beneath the -20 C isotherm, so a rogue lightning flash cannot be ruled out if buoyancy is larger/deeper than progged. Thunderstorms may form tonight over Atlantic waters where sea-air thermodynamic fluxes supply greater low-level moisture and steepen lapse rates. However, thunder potential appears too small and conditional inland to assign a general-thunder area. Farther west, the synoptic ridge will shift from its present position -- over the northern Intermountain region to northern High Plains -- reaching the bulk of the Great Plains States by 12Z. A cut-off height weakness was apparent initially, with weak vorticity lobes or weakly closed circulations near the Four Corners and near YUM. As these two lobes pivot oppositely of each other (the northern one moving erratically west-northwest toward the Capitol Reef area and the southern drifting eastward near the international border), difluent flow aloft will persist and spread across much of northwestern MX and southeastern AZ. Diurnal heating will steepen low/middle-level lapse rates amid scant moisture, yielding MLCAPE less than 100 J/kg north of the border and along/east of I-19. The convection may become deep enough for isolated flashes, but it still appears very conditional, and the greater moisture and lightning risk will be over Sonora. ...Edwards.. 01/30/2024 $$ = = = 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) .