Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Feb 19 2024 05:53:54 ACUS01 KWNS 190553 SWODY1 SPC AC 190552 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1152 PM CST Sun Feb 18 2024 Valid 191200Z - 201200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE SACRAMENTO VALLEY IN CENTRAL INTO NORTHERN CALIFORNIA... ....SUMMARY... An isolated tornado is possible across portions of the Sacramento Valley of central into northern California Monday afternoon and early evening. ....Synopsis... Thunderstorm potential, including the potential for strong to severe thunderstorms, will be focused across the West Coast into the northern Great Basin. Late evening water-vapor imagery depicts a broad upper-level cyclone off the West Coast, which is forecast to move onshore through the day. As this occurs, cold temperatures aloft will promote adequate buoyancy across much of the region for isolated to scattered thunderstorms today and tonight. ....Central to northern California/Sacramento Valley... A broad swath of isentropic ascent ahead of the upper wave is promoting stratiform precipitation over much of CA as of 05 UTC Monday. This band will gradually shift east through mid/late morning with some clearing anticipated by early afternoon. A plume of low to mid-50s dewpoints is noted in 05 UTC surface observations shifting northward from the central/southern CA coast into the Sacramento Valley. While diurnal insolation will likely be muted by mid/high-level cloud cover, the combination of cooling temperatures aloft with the influx of low-level moisture should promote adequate buoyancy for at least shallow convection through the northern half of the Sacramento Valley. Mid and upper-level flow is forecast to strengthen through the day with the approach of the upper trough, leading to elongating hodographs through the CAPE bearing layer. Southeasterly flow through the Valley will promote strong low-level shear with forecast hodographs depicting favorable low-level curvature for ESRH values on the order of 100-200 m2s2. This kinematic environment in the presence of strong, broad ascent should promote discrete to semi-discrete storm modes. While the limited thermodynamic environment will be a modulating factor, rotating supercells appear possible and should pose a threat for hail, damaging wind gusts, and a couple of brief tornadoes. ...Moore.. 02/19/2024 $$ = = = 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) .