Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Jan 09 2023 06:02:26 ACUS02 KWNS 090602 SWODY2 SPC AC 090600 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CST Mon Jan 09 2023 Valid 101200Z - 111200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN/CENTRAL CALIFORNIA... ....SUMMARY... Isolated strong to severe thunderstorms capable of producing damaging winds and perhaps a brief tornado may occur Tuesday across parts of southern/central California. ....Southern/Central California... A powerful and highly amplified upper trough will move from the eastern Pacific across the western CONUS on Tuesday. An embedded shortwave trough with associated strong mid-level jet is forecast to advance eastward over parts of southern/central CA and into the Southwest through the period. Strong ascent preceding the shortwave trough and weak instability may support a low-topped band of convection along/near the central CA Coast at the beginning of the period early Tuesday morning. Strong deep-layer shear will likely exist across coastal portions of southern/central CA as enhanced mid-level west-southwesterly winds overspread these areas. Guidance suggests 40-50+ kt of effective bulk shear will be present, which will support updraft organization. The main uncertainty continues to be the degree of instability that will be realized. With a persistent southwesterly low-level fetch, low to mid 50s surface dewpoints should advect slightly inland over parts of southern CA through Tuesday morning. Even though diurnal heating will likely be hampered by widespread cloudiness, cooling mid-level temperatures and steepening lapse rates aloft are expected as the shortwave trough moves eastward through the day. This should help compensate for the limited daytime heating, and around 200-500 J/kg of MLCAPE may develop. The forecast combination of weak, but potentially sufficient, instability and strong deep-layer shear suggests that some severe threat will probably exist with thunderstorms spreading inland along the central to southern CA Coast Tuesday morning and early afternoon. A modestly enhanced low-level jet should also be present over these regions. Given the strength of the flow aloft, and potential for a low-topped band of convection to move generally southeastward along/near the coast, isolated damaging winds should be the primary severe threat. But, enough low-level shear to support updraft rotation will also be present. A brief tornado appears possible, especially if a supercell can develop and be sustained. This isolated/marginal severe threat should remain confined to mainly coastal regions of southern/central CA, as appreciable low-level moisture is not expected to advance very far inland. ...Gleason.. 01/09/2023 $$ = = = 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) .