CNN  — 

Californians pummeled by an onslaught of dangerous storms will get deluged again as another atmospheric river threatens more deadly flooding.

More than 30 million people in California were under flood watches Monday that cover much of the state, including Los Angeles, San Francisco, Fresno and Sacramento.

The brunt of the storm is expected to lash Northern and central California beginning late Monday and Southern California starting Tuesday.

Already, a levee breach in Monterey County blamed on devastating weekend flooding has prompted evacuation alerts for thousands. And Monterey Bay residents could soon find themselves on a virtual island, cut off by more floodwater.

About 20 swift-water rescue teams in more than 10 counties have been positioned ahead of the looming storm, the California Governor’s Office of Emergency Services said Monday, following dozens of water rescues in recent days.

This new wave of menacing weather comes on the heels of a deadly atmospheric river – a long, narrow band of moisture that can carry saturated air thousands of miles like a fire hose. It will be the 11th to pummel the West this winter season.

From severe flooding to lengthy droughts, the intensity of water-related disasters around the world has increased over the past two decades as global temperatures climbed to record levels, new research shows.

California’s new storm could exacerbate flooding and damage in some places. Already, residents in central and Northern California are crowding into shelters amid mudslides, rushing rivers, collapsed bridges and impassable roads.

weather excessive rainfall outlook monday tuesday 03132023

Intense rainfall totals up to 8 inches are possible across parts of Northern and central California.

South of San Francisco, parts of Monterey County – including Salinas – could get cut off by flooding on the Salinas River, officials said. Those at risk “can and should seek shelter” with family or friends or at one of the county’s evacuation shelters, Monterey County officials said.

The storm also could complicate efforts to repair a levee in Monterey County that was breached around midnight Friday by the swollen Pajaro River. Evacuation alerts for 5,000 residents could expand.

Water rushed through the more than 120-foot break and into nearby Pajaro, forcing thousands to flee as crews rescued close to 200 others, Monterey Sheriff Tina Nieto said. Now, officials fear more rescues will be needed with this next storm.

“The situation is dynamic and evolving,” said California Department of Water Resources Flood Division Manager Jeremy Arrich. Construction crews have continued working to stabilize the levee and engineers are focusing on both short- and long-term fixes, he said. The flood division is reaching out to other levee managers in the region ahead of the storm to ensure safety and stability.

Many Pajaro residents are farmworkers who may not only lose property but also the ability to earn a living for some time if the continued flooding impacts agriculture, said Luis Alejo, chair of the Monterey County board of supervisors.

“These are the folks who can least afford this type of hardship,” he said.

What to expect as the storm moves in

A breached levee and flooded river are seen Sunday in Pajaro, California.

This new wave of storms is bearing down on areas already buried by heavy snowfall from the past two weeks. Melting snowpack is also expected also play a role in prolonging flooding over the upcoming days, forecasters say.

The National Weather Service’s Storm Prediction Center issued a Level 4 of 4 risk of excessive rainfall – the center’s highest risk assessment – that could lead to flash flooding Tuesday along the coast from portions of Monterey County in central California southward to Santa Barbara.

The rain is expected to start intensifying late Monday and, combined with snowmelt, is forecast to fuel more flooding from Tuesday into Wednesday, the National Weather Service said.

Forecasters warned of “considerable flooding impacts” below 5,000-foot elevations across large portions of central California into Tuesday. Creeks and streams already bloated from previous inundations are at risk of overflowing due to more rain and snowmelt.

Mammoth Lakes firefighters respond to a propane heater leak and small fire at a shuttered restaurant surrounded by snowbanks Sunday.

“Even though precipitation totals during this upcoming storm will be far from historic, the impacts will be probably greater than the precipitation totals would otherwise suggest,” UCLA climate scientist Daniel Swain said.

In Southern California, rain could fall as fast as 1 inch per hour over the mountains and foothills. The National Weather Service office in Los Angeles warned residents could expect fallen trees, downed power lines, along with flooded roads and mudslides.

There were 32 shelters open across 13 California counties Monday, according to the state’s emergency services office. More than 600 people have stayed at shelters, the office said, mostly in Santa Cruz and Monterey counties.

‘We are now an island’

Cars and homes are engulfed by floodwaters in Pajaro, California, on Saturday.

Rescue crews have plucked dozens of residents from perilous floodwater as torrential rain over the past week pushed rivers and creeks over their banks.

About 200 people have been rescued in Monterey County alone, according to Sheriff Tina Nieto.

The county activated both its search and rescue team and rescue dive team to work 24-hour shifts due to the flooding, Undersheriff Keith Boyd said Monday.

In the county’s hard-hit Pajaro area, officials have evacuated close to 2,000 people. A school, two mobile home parks and about 800 homes in the area were impacted by flooding, Boyd said.

The California Highway Patrol posted dramatic video of a helicopter rescue in King City, where a driver was trapped in the Salinas River.

“The rising river washed a driver and his car away but the driver was able to escape the vehicle and get to an island in the middle of the flooded Salinas River,” the highway patrol posted Sunday.

Evacuation orders remain in parts of Kern County as the swollen Kern River swept away a shed, a hot tub and full-size trees in Kernville, a resident said.

“The river is now surrounding some RVs and mobile homes. It’s really unbelievable,” said Danny Housh, who has worked in Kernville for 17 years and said he’s never seen anything like this.

To the north, intense rainfall Friday in Santa Cruz County left about 700 Soquel residents trapped after a pipe failure collapsed the only road linking the community to the region, said Steve Wiesner, the county’s assistant public works director.

“We are now an island,” resident Molly Watson told CNN.

Another hard-hit area was Tulare County, where video from Springville showed devastating damage after Friday’s severe flooding.

“It’s quite heartbreaking,” Hatti Shepard told CNN. “Many hardworking people displaced with losses of home and possessions.”

CNN meteorologists Dave Hennen and Haley Brink and CNN’s Rachel Ramirez, Tina Burnside, Mike Valerio and Sharif Paget contributed to this report.