SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0654 PM CST Wed Dec 24 2025 Valid 250100Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ALONG MUCH OF THE CALIFORNIA COAST AND PORTIONS OF THE CENTRAL VALLEY... ...SUMMARY... An isolated risk for severe/damaging gusts and perhaps a brief tornado will exist through tonight along much of the California Coast and portions of the Central Valley. ... 01Z Update ... Multiple bands of convection look likely this evening into the early morning hours as a deepening surface low approaches the California coast. The strongest convective elements within this first band, currently approaching the San Francisco Bay area, will be capable of producing gusty winds as it moves inland. Wind fields will strengthen overnight in response to the approaching low. This will maintain sufficient low-level theta-e advection to support modest low-level instability through Christmas morning. Numerical guidance this evening indicates a more intense band of convection will approach the central and northern California coast in the 08-12Z (12-4AM PT) window, quickly moving into northern portions of the Central Valley. Given the modest instability and strong wind fields, isolated strong wind gusts and a brief tornado will be possible overnight, especially along the coast. Elsewhere along the California coast, low-level moist advection will persist through the night supporting localized convective development. For the same reasons listed above, an isolated strong wind gust or brief tornado would be possible with these convective elements. ... Central Valley ... Thunderstorms have developed this afternoon across portions of the Central Valley near Sacramento. Surface-based instability around 500 J/kg within a strongly sheared environment will support an isolated wind threat. Should convective elements become more cellular, the low-level wind fields would support a brief tornado, especially in areas where surface-based instability can be realized. This activity will lift generally northward across the Central Valley through this evening. ..Marsh.. 12/25/2025
