SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CST Mon Dec 22 2025 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL AND SOUTHERN COASTAL CALIFORNIA AND PARTS OF THE CALIFORNIA CENTRAL VALLEY... ...SUMMARY... Isolated strong to locally severe thunderstorms are possible on Wednesday and Wednesday night across portions of California. ...California... An upper trough over the eastern Pacific and upper ridge over the Great Plains will maintain a belt of strong to intense cyclonic flow across CA north-northeastward into the Interior West. A lead shortwave trough will move from the OR/CA border northward into WA during the day, while an upstream disturbance moves from the eastern Pacific northeastward into central and northern CA after dark. A prolonged period of scattered showers and episodic periods of isolated thunderstorms are forecast across CA on Wednesday into Wednesday night. Relatively cold mid-level temperatures (-20 to -24 deg C at 500 mb) will aid in the development of weak instability during the afternoon across portions of the central valley. Elongated hodographs coupled with the potential for a short-duration period of modest surface-based destabilization could yield an isolated risk for a couple of weakly rotating storms. A risk for localized squalls moving inland near the immediate coast from parts of southern into central CA may focus primarily late Wednesday into Wednesday night ahead of the approaching disturbance. Elsewhere, tranquil conditions will prevail across much of the CONUS. ..Smith.. 12/22/2025
