‘Life-threatening’ flooding feared in Northern California as storms cause rivers to swell #usa


Another in a series of powerful winter storms unleashed heavy rain in Northern California on Monday, causing widespread flooding in Santa Cruz County and beyond as rivers began to swell across the region.

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.

In Santa Cruz County, evacuations were underway and major flooding was reported in Felton Grove and Paradise Park after the San Lorenzo River rose over its banks and flowed out into the surrounding community. Videos posted on social media showed muddy water rising up to stop signs in Felton Grove as the San Lorenzo River raged nearby filled with logs and other debris.

With roadways flooded, rescue crews struggled to get into flooded neighborhoods where residents reported being trapped in their homes. The crews launched a jet ski to get through water.

“Travel will be extremely difficult, if not impossible, throughout the county this morning. We are urging people to stay at home if possible,” the county wrote on Twitter.

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.

“This is just the middle of what has already been a very wet and active pattern – and what is expected to be one, really, for at least another week or so,” said Daniel Swain, a climate scientist at UCLA.

The atmospheric river is kind of “draped along the central coast” with heaviest rainfall from about Monterey County into Santa Barbara County, although there are also heavy rains extending southwest and northeast, he said. One big concern is that the atmospheric is going to slow down a bit along the central coast, bringing instability that may maximize rainfall rates.

There are also potential convective elements such as thunderstorms, which are “the kinds of conditions that have a tendency to produce significant flash flooding and debris flows in the transverse ranges of Southern California, in particular along the Big Sur coasts,” he said.

“This is a major, potentially life-threatening event, but it also I don’t think we can call it the catastrophic flood that California has been worried about,” he added. “This is neither as intense nor as long in duration nor as widespread as the kind of events that we are talking about, although it certainly gives us a taste of what things look like as we had a little bit more in that direction.”

It’s not just the total amount of rain that matters, but it’s how quickly it falls, Swain said, noting that “rainfall rates during the storm – or the maximum amount of precipitation per hour – have been pretty high, and that is indeed why we’re seeing such significant flooding in some areas.”

He said portions of the Bay Area and Northern California may even see some sunshine this afternoon, but it will be short lived as another intense pulse of strong winds and heavy downpours moves in Monday evening.

“Don’t be fooled by the sunny breaks in Northern California later today – there is more on the way imminently within the next 12 hours,” he said.

Late Sunday, President 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 snow 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.

As the rain continued to pour Monday morning, cars flowed gingerly along the peninsula’s Highway 280, which runs along the San Andreas fault through the foothills of the Santa Cruz Mountains. Usually a high-speed thoroughfare — where traffic seems to cruise around 80 mph — the few drivers that were out were crawling, taking the occasional hydroplane with care.

Along Woodland Avenue in Menlo Park, where emergency officials warned that the San Francisquito Creek could flood, sandbags were piled high along the creek edge in segments. Several driveways were also barricaded.

Creek monitors showed the San Francisquito rising quickly on Monday, approaching flood stage at the Pope Chaucer Bridge, which connects Palo Alto and Menlo Park.

Evacuation warnings or orders were also issued in parts of Santa Clara, Alameda, Sacramento, Sonoma, and Monterey 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.

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.”

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