Atmospheric River Storm Brings Flood Risks to California

An atmospheric river storm began battering California on Thursday, delivering heavy rain, strong winds and early-season snow across the state through the weekend, with forecasters warning of flash flooding and debris flows in wildfire-scarred areas of Southern California.

The system, which arrived in Northern California first, prompted flash flood threats in the Bay Area and Sacramento regions on Thursday, where rainfall already exceeded 1 inch in places like San Francisco and Napa. Downed trees blocked roads in San Francisco's Western Addition and Santa Rosa, while flooding closed sections of roadway near Sonoma County Airport. Solo vehicle crashes, including an overturned truck on Highway 152 and a collision involving a California Highway Patrol cruiser on Highway 17, led to temporary lane closures in Santa Cruz County. A brief ground stop at San Francisco International Airport occurred due to high winds.

As the storm shifts south, Southern California faces its most intense impacts from late Thursday through Saturday. The National Weather Service issued flood watches for Los Angeles, Orange, Riverside, San Bernardino, San Diego and Ventura counties, effective through Saturday...