Houses are partially submerged Sunday in Manteca, California, after heavy rain caused the San Joaquin River to spill over.
CNN  — 

Swaths of California still saturated by ruthless storms will get walloped by another atmospheric river, spawning fears of renewed flooding and forcing some residents to flee.

The state has already been hammered by at least 11 atmospheric rivers this season. An atmospheric river is like a fire hose that carries saturated air from the tropics to higher latitudes, dumping relentless rain or snow.

The last, which struck California last week, left soil overly saturated and vulnerable to new flooding and rapid runoffs, the National Weather Service said.

The next atmospheric river is expected to slam California from late Monday night through Wednesday.

“The system will bring heavy rain and a flood threat, heavy snow with dangerous travel and high winds gusting over hurricane force” in some places, CNN Meteorologist Dave Hennen said.

Peak wind gusts of 60 to 80 mph are forecast for the mountains and deserts of Southern California, where power outages will likely develop, Hennen said.

The imminent storm system is expected to dump 1 to 3 inches of rain across the lower elevations and 2 to 4 inches across the foothills of Southern California through Thursday. Nearby Arizona could get up to 3 inches of rainfall.

The Weather Prediction Center on Monday raised the flood threat for portions of Southern California to a level 3 of 4, which is a moderate risk. More than 15 million people are included in the category in coastal areas from Los Angeles to San Diego.

“When adding runoff from the steep nearby mountains where rainfall totals may exceed 4 inches, numerous flash floods are likely,” the center warned. “The timing of the heaviest rain also favors added impacts, as they will likely be ongoing during the Tuesday morning commute.”

Thousands of residents were under evacuation orders Sunday in two small central California towns, Alpaugh and Allensworth. Officials worried roads could become impassable and isolate residents, the Tulare County Sheriff’s Office said.

First responders from dozens of agencies, including the California National Guard, were out Sunday afternoon helping residents evacuate – a sight that has become familiar in the flood-ravaged state.

“The devastation is indescribable,” Tulare County farmer Brandon Mendonsa told CNN affiliate KFSN. “The water is still coming – this is far from being done.”

Kristen Vogt and her dog Roo walk home through floodwater Sunday in Manteca, California.

Ferocious winds will whip the state

More than 25 million people are under alerts for strong winds from California into Nevada and Arizona. Wind gusts of 40 mph to 55 mph are expected along the coast and in the valleys of Southern California Tuesday.

In the mountains, gusts up to 75 mph are likely and may be strong enough to down trees and power lines from the central California coast to Southern California, the National Weather Service said.

In the Sierra Nevada and Southern California mountain ranges, several feet of snowfall in some of the highest terrains could make travel hazardous.

Winter storm warnings were in effect for the higher terrain of Southern California, as the highest elevations could see 2 to 5 feet of snow.

“Travel could be very difficult to impossible. The hazardous conditions could impact the morning or evening commute. Very strong winds could cause extensive tree damage,” the weather service warned.

In the Sierra Nevada Mountain Range, an additional 1 to 4 feet of snowfall is possible late Monday through Wednesday afternoon. The San Bernardino Mountains are also under a winter storm watch, with snowfall expected to reach up to 4 feet through Wednesday with gusts up to 85 mph.

Severe drought cut by half

While the atmospheric rivers have upended life for many Californians – damaging homes and livelihoods – the ensuing rainfall has also helped put a dent in the state’s historic drought.

Last week’s atmospheric river alone shattered daily rainfall records in Los Angeles, Santa Barbara and Santa Maria.

There’s been so much rain that the Southern California water board called off emergency drought conservation measures for more than 7 million people.

Severe drought in California was cut in half from the previous week, now covering only 8% of the state, down from 80.6% just three months ago, according to the US Drought Monitor. Just over a third of the state remains in some level of drought.

The abnormally wet winter – combined with recent storms – wiped out exceptional and extreme drought in California for the first time since 2020, according to the National Oceanic and Atmospheric Administration.

“Moderate to exceptional drought coverage across the U.S. is at its lowest since August 2020 and is likely to continue improving, or end entirely, across much of California and the Great Basin,” NOAA forecasters said.

As the snowpack melts in the coming months, it’s expected to further improve drought conditions across much of the western US, according to NOAA. But, that could also mean more floods.

“Approximately 44% of the U.S. is at risk for flooding this spring,” said Ed Clark, director of NOAA’s National Water Center. “California’s historic snowpack, coupled with spring rain, is heightening the potential for spring floods.”

CNN’s Taylor Ward, Haley Brink, Rachel Ramirez and Monica Garrett contributed to this report.