Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Mar 18 2024 04:30:06 ACUS02 KWNS 180429 SWODY2 SPC AC 180428 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1128 PM CDT Sun Mar 17 2024 Valid 191200Z - 201200Z ....NO SEVERE THUNDERSTORM AREAS FORECAST... ....SUMMARY... The risk for severe thunderstorms appears negligible across the U.S., Tuesday through Tuesday night. ....Synopsis... Models continue to suggest that a high may become at least a bit better established near/southwest of the Gulf of Alaska vicinity during this period, within amplified split flow emanating from the western mid-latitude Pacific. Downstream, as the blocking inland of the U.S. Pacific coast continues to break down, the remnant Southwestern low is forecast to elongate east-northeast of the lower Colorado Valley, toward the southern Rockies. To the east of this regime, confluent flow will generally be maintained to the east of the Rockies, as another vigorous short wave trough digs across the international border into the Upper Midwest/Great Lakes region. It appears that this will be accompanied by a reinforcing low-level cold intrusion, as far south as the Ohio and lower Missouri Valleys by 12Z Wednesday, and contribute to the maintenance of broad mid-level troughing east of the Mississippi Valley through the western Atlantic. At the same time, models indicate that upper ridging may build east-northeast of the subtropical latitudes, into portions of the southern Great Plains and Gulf Coast states. In the wake of the mid-level troughing, the boundary-layer across all but southwestern portions of the Gulf Basin will likely have been stabilized by an initial intrusion of cool/dry air by early Tuesday. While a developing southerly low-level return flow may contribute to low-level moistening as far north as Deep South Texas by late Tuesday night, this will likely be preceded by the advection of a pronounced warm layer (centered around 700 mb) east of the Rio Grande river through much of central and southern Texas. ....Deep South Texas... At least some model output (perhaps most notably the NAM and ECMWF) continues to suggest that a developing area of mid-level ascent, aided by warm advection near the leading edge of the warm air emerging from the Mexican Plateau, may contribute to weak destabilization and elevated convection, some of which could become capable of producing lightning early Tuesday. ....Colorado Plateau into southern Rockies... Beneath the mid-level cold pool (including 500 mb temperatures still around or below -20 to -22C) slowly shifting eastward across the region, destabilization aided by daytime heating probably will be sufficient to contribute to scattered weak afternoon and evening thunderstorm activity. ....California... Convective potential for Tuesday remains unclear beneath the weakening mid/upper ridging across the Sierra Nevada, and the residual cyclonic flow across parts of the Transverse and Peninsular Ranges of southern California. However, most model output suggests that destabilization supportive of isolated to widely scattered weak thunderstorm activity is possible, generally focused along the higher terrain. ...Kerr.. 03/18/2024 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .