LOS ANGELES — Another in a series of powerful winter storms is bearing down on Northern California on Monday prompting concerns over flooding and hazardous winds that triggered President Joe Biden to declare an emergency in the state.
A series of atmospheric rivers that pummeled coastal communities last week and left more than 400,000 without power in California on Sunday will be followed by two major episodes of heavy rain and mountain snow in the next several days. Rivers are expected to reach flood level, debris flows could be possible in burn areas and powerful winds could wreak havoc from the “energetic and moisture-laden parade of cyclones that are aiming directly for California,” according to the National Weather Service.
Late Sunday, Biden approved an emergency declaration for California which authorizes the Federal Emergency Management Agency to coordinate disaster relief efforts and provide emergency resources, the White House said in a statement.
“We expect to see the worst of it still in front of us,” Gov. Gavin Newsom said Sunday. “We’re anticipating very intense weather coming in [Monday] and Tuesday morning.”
Heavy rain was already falling over the San Francisco Bay Area early Monday. The region is expected to see between 3 and 5 inches of rain and gusts reaching up to 45 mph from the weather system. The Sierra Nevada will likely see heavy rain exceeding 6 feet across higher elevations through Tuesday night.
“The cumulative effect of successive heavy rainfall events will lead to additional instances of flooding. This includes rapid water rises, mudslides, and the potential for major river flooding. Susceptible terrain and areas near recent burn scars will be most at risk for debris flows and rapid runoff,” according to a forecast from the National Weather Service in the Bay Area.
Evacuation warnings or orders were issued in parts of Santa Clara, Alameda, Sacramento, Sonoma, Monterey and Santa Cruz counties, with forecasts suggesting that swollen rivers could flood businesses and homes.
The weather service on Monday issued flash flood warnings for the Dolan fire burn scar in Monterey County, along with portions of Santa Cruz, Watsonville and Scotts Valley. The agency also issued flood warnings for the Carmel River at Robles Del Rio in Monterey County and the Russian River in Guerneville.
San Jose officials were gearing up for what could be the worst flooding to hit the San Francisco Bay Area’s most populous city since the surprise flooding in 2017 of Coyote Creek, which forced more than 14,000 residents out of their homes.
Water district officials warned of possible flooding in San Jose at the Guadalupe River near the Tamien station of the Caltrain commuter rail system, affecting the Northern Cross neighborhood, Ross Creek at Cherry Avenue south of downtown, and Upper Penitencia Creek near the Berryessa/North San Jose BART station.
The Santa Clara Valley Water District on Sunday issued an “extreme weather alert.” Flooding is possible in the coming days in Palo Alto, Menlo Park, Sunnyvale, Morgan Hill and Gilroy.
The Russian River could at Guerneville could reach flood stage on Tuesday, according to the California Nevada River Forecast Center.
Flooding along some rivers could happen even after the rain stops on Tuesday because of continuing runoff, said Brayden Murdoch, a meteorologist with the National Weather Service in the Bay Area.
“Some of the peaks are actually going to be between systems,” he said. “But there’s already quite a strain on some of our main rivers in the area as well as lagoons and deltas.”
Evacuation warnings were issued downstream of two full reservoirs in Santa Clara County: the Uvas Reservoir northwest of Gilroy, whose water flows into Uvas Creek; and the Pacheco Reservoir, which empties into Pacheco Creek alongside Highway 152 — a main route between the San Francisco Bay Area and Interstate 5.
Evacuation warnings in Santa Cruz County included towns east and southeast of Santa Cruz, including Soquel, Seacliff, Rio del Mar and Watsonville, which borders the Pajaro River.
The Carmel, Pajaro and Big Sur rivers could reach flood stage on Monday, and the Salinas River on Tuesday. The rising Carmel River prompted officials to issue an evacuation warning along the Carmel Valley.
Alameda County issued evacuation warnings for the hills east of Hayward and Fremont and west of Pleasanton. Sacramento County issued an evacuation order for the Wilton area along the Cosumnes River, whose waters breached levees over New Year’s Eve, killing three motorists whose bodies were found in or near submerged cars near Highway 99.
“Already we’ve seen plenty of reports of mud on the road and downed trees,” Murdoch said. “We’ve had some power flashes and roadway flooding, especially in those areas that have seen that heavier rain develop. There’s a lot going on with this system.”
