Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Mar 28 2023 17:24:47 ACUS02 KWNS 281724 SWODY2 SPC AC 281723 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Tue Mar 28 2023 Valid 291200Z - 301200Z ....NO SEVERE THUNDERSTORM AREAS FORECAST... ....SUMMARY... Severe thunderstorms are not expected on Wednesday. ....Synopsis... A progressive mid-level flow pattern is forecast to gradually amplify across much of the CONUS D2/Wednesday. Large-scale troughing over the eastern half of the country will shift eastward as it becomes broader before eventually moving offshore. To the west, a shortwave ridge will build over the center of the country as a second trough/closed low moves onshore across the West Coast. At the surface, high pressure initially over the Midwest will gradually strengthen and shift eastward with time in the wake of a cold front sweeping to the south. Farther west, low pressure will move onshore over central CA as several weak areas of low pressure slowly consolidate over the Intermountain West and the lee of the Rockies. ....South Florida... Across the southern Peninsula, afternoon heating ahead of the slow-moving cold front and sea breeze boundaries should support the development of scattered thunderstorms Wednesday afternoon and evening. Area model soundings show only modest mid-level lapse rates and weak to moderate uni-directional shear profiles below 6 km. Despite some lingering enhanced flow aloft at the base of the departing northeastern US trough, storm organization potential appears relatively low. Afternoon mixing, and the somewhat enhanced flow aloft may allow for an isolated stronger downdraft capable of strong to severe winds. However confidence is limited, and severe probabilities are expected to remain below 5 percent. ....California... As the upper low moves onshore over southern and central CA early D2/Wednesday, strong flow aloft, mid-level height falls, and cold advection aloft may allow for sufficient destabilization to support isolated to scattered thunderstorms. Confidence in storm development is highest across portions of the southern Central Valley, closest to the H5 -30C cold pocket aloft. Despite the cool temperatures aloft, widespread cloud cover and precipitation from subtropical moisture should limit diurnal heating and subsequent lapse rates/instability. Vertical wind profiles could briefly support some transient organized updrafts capable of small hail, but the limited instability and weak low-level and effective shear should limit the severe potential below Marginal criteria. ....Eastern Great Lakes/Northeast US... As the aforementioned eastern US upper trough shifts eastward, a strong surface cold front will move out of southern Canada into the eastern Great Lakes and Northeast. Marginal buoyancy with steep lapse rates may allow for a few lightning flashes to develop within a band of strongly forced, low-topped, convection along the front Wednesday afternoon/evening. Winds in the lowest few km are not expected to be overly strong, but may still support a few sub-severe gusts with the convective band as it moves eastward through the afternoon. A thunder area has been added. ...Lyons/Jewell.. 03/28/2023 $$ = = = 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) .