Weather Alerts For San Geronimo, CA

URGENT - WEATHER MESSAGE National Weather Service San Francisco CA 323 AM PST Wed Dec 24 2025 San Francisco-Marin Coastal Range-Sonoma Coastal Range-Coastal North Bay Including Point Reyes National Seashore-San Francisco Peninsula Coast-Southern Salinas Valley/Arroyo Seco and Lake San Antonio-Santa Lucia Mountains and Los Padres National Forest- Northern Salinas Valley/Hollister Valley and Carmel Valley- Northern Monterey Bay-Southern Monterey Bay and Big Sur Coast- 323 AM PST Wed Dec 24 2025 ...HIGH WIND WARNING NOW IN EFFECT UNTIL 8 AM PST THIS MORNING... * WHAT...Southeast winds 30 to 40 mph with gusts up to 65 mph expected. Isolated areas along the coast may see a few gusts up to 75 mph. * WHERE...The Salinas and Carmel Valleys and Hollister Area, Monterey Bay and the Big Sur Coast, The Marin Hills, Western Sonoma County Hills, Interior Monterey County and the Santa Lucia Range, San Francisco, Coastal North Bay Including Point Reyes National Seashore, and San Francisco Peninsula Coast. * WHEN...Until 8 AM PST this morning. * IMPACTS...Damaging winds will blow down trees and power lines. Widespread power outages are expected. Travel will be difficult, especially for high profile vehicles. Damaging winds could down trees, snap power lines, and result in property damage. Widespread power outages are possible. Travel could be extremely difficult and hazardous, especially for high profile vehicles. PRECAUTIONARY/PREPAREDNESS ACTIONS... People are urged to secure loose objects that could be blown around or damaged by the wind. Secure loose outdoor objects that could be blown around or damaged by the wind. &&

Flood Watch National Weather Service San Francisco CA 1139 PM PST Tue Dec 23 2025 Marin Coastal Range-Sonoma Coastal Range-North Bay Interior Mountains-Coastal North Bay Including Point Reyes National Seashore-North Bay Interior Valleys- Including the cities of Novato, Lagunitas-Forest Knolls, South Santa Rosa, Woodacre, Napa, Angwin, Petaluma, Tamalpais-Homestead, Rohnert Park, Santa Rosa, Sausalito, and San Rafael 1139 PM PST Tue Dec 23 2025 ...FLOOD WATCH REMAINS IN EFFECT THROUGH FRIDAY EVENING... * WHAT...Flooding caused by excessive rainfall continues to be possible from multiple lines of showers and thunderstorms, strong at times, moving across the area. * WHERE...The Northern San Francisco Bay Area (Napa, Sonoma, and Marin counties). * WHEN...Through Friday evening. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Creeks and streams may rise out of their banks. Low water crossings may become flooded. Flooding may occur in poor drainage and urban areas. * ADDITIONAL DETAILS... - Multiple rounds of moderate to heavy rainfall are expected across the North Bay through Friday evening. An additional 3-5" is possible over the North Bay Mountains and 2-3" over the North Bay Valleys by Friday. Nuisance flooding will increase throughout the week with sharp rises in smaller creeks and minor flooding along some of the mainstream rivers (Russian River, Napa River). Debris flows are possible particularly for the Pickett Burn Scar. - http://www.weather.gov/safety/flood PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop. &&

There is a Marginal Severe Storm Risk for your location. Continue reading for today's outlook from the National Weather Service's Storm Prediction Center. -------------------- National Severe Storm Outlook THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS COASTAL CALIFORNIA AND THE CENTRAL VALLEY SUMMARY Thunderstorms with marginally severe wind gusts, small hail and potentially a brief tornado will be possible from Wednesday into Wednesday night along parts of the California coast, and inland across the San Joaquin Valley. Synopsis A high-amplitude midlevel pattern will persist on Wednesday, characterized by a deep trough across the eastern Pacific and a building ridge across the Plains. This pattern will maintain a broad belt of intense cyclonic flow across California into the Interior West. Throughout the day, an initial shortwave trough will continue lifting northeast from the eastern Pacific into the Pacific Northwest, while the attendant surface low lifts more northward along the coast toward Washington. Late on Wednesday a second, more potent trough will approach central and northern California -- primarily after dark. This setup will facilitate a prolonged period rain and embedded thunderstorms across California and portions of the Interior West into Thursday. California Coast Strong ascent and strengthening onshore flow will aid in modest destabilization Wednesday morning ahead of a surface cold front. An ongoing band of convection is expected across the central and southern coastal areas associated with the strongly forced ascent along the advancing cold front. Given the presence of a strong low-level jet (locally exceeding 50 knots at 1 km AGL), there is a risk that these strong winds will mix to the surface within the strongest convection resulting in damaging wind gusts. Forecast soundings across the area do maintain some low-level curvature ahead of the convective line, such that any convective element able to interact with true surface-based buoyancy would have the potential for a brief tornado. In the wake of the morning convection, a secondary surface low will intensify during the afternoon and overnight as it approaches the northern California coast. This will likely trigger another round or two of broken, low-topped convection along a second cold front. Despite weaker instability than with the morning convection, the strength of the wind fields would suggest an ongoing risk for isolated wind damage as this convection moves inland. Central Valley Cold midlevel temperatures and increasing height falls will overspread surface dewpoints in the 40s to perhaps low 50s. Although buoyancy will remain modest (MUCAPE at or below 500 J/kg), the presence of a powerful midlevel jet in excess of 100 knots will support long hodographs. This combination of modest instability and large/long hodographs may support a threat for semi-organized convection, including some potential for supercells. The strongest storms will be capable of producing damaging gusts, hail, and a brief tornado before the convection shifts east into the higher terrain and weakens.