Millions are at risk from tornadoes in the South, with the storm threatening the Midwest

(CNN) – A deadly California winter storm now threatens tornadoes in the South and heavy snow, freezing rain and sleet in the Midwest.

More than three million people are under a hurricane watch as of 10 p.m. Miami time in parts of Arkansas, Texas, Louisiana and Oklahoma.

Hurricanes are not the only danger in the region. The Storm Prediction Center warned of the possibility of hail and hurricane winds of up to 110 kilometers per hour “until late at night in most parts of the region.”

Anyone in tornado risk areas should seek safe shelter immediately, said Brad Bryant, a meteorologist in charge of the National Weather Service office in Shreveport, Louisiana.

“If you wait for a warning to be issued, it’s too late,” Bryant said Monday. “You should have a safe haven plan in place before these storms.”

Bryant encouraged those who need help — especially those living in mobile homes — to contact local emergency managers or law enforcement to see what shelter options they have.

“Since mid-November, we’ve had three rounds of severe weather and fatalities, mostly in mobile homes,” Bryant said.

From Missouri to the Gulf Coast of Mexico, more than 30 million people are at risk of severe weather Monday, according to CNN meteorologist Dave Hennen.

More tornadoes and damaging winds are likely Tuesday across parts of Louisiana, Mississippi and Alabama as the storm moves east.

Farther north, more than 15 million people from Utah to Wisconsin are under a wintry weather warning Monday.

The same storm system caused record rains and deadly flooding in drought-stricken California over the weekend. Another bout of heavy rains this week could exacerbate dangerous flooding.

Traveling would be dangerous, if not impossible.

Snow is expected at 1 to 2 inches per hour across the Plains and Midwest from Nebraska to southwest Minnesota, leaving a total of more than 12 inches of snow by the end of Tuesday. An avalanche may be accompanied by thunder.

“These extreme rates combined with high winds will produce areas of drifting and swirling snow, resulting in snow-covered roads, reduced visibility and difficulty in travel,” the Weather Prediction Center said.

Significant ice buildup can lead to power outages and treacherous travel conditions.

Freezing rain could accumulate more than half an inch of ice from northeastern Nebraska to northwest Iowa to southern Minnesota by late Monday through Tuesday.

“Travel will become hazardous, if not impossible, later tonight (through) Tuesday in many areas,” the National Weather Service in Sioux Falls said Monday.

California may see more flooding this week

Meanwhile, storms and torrential rain left three cars submerged on Dillard Road in Sacramento, California, after heavy rains on New Year’s Eve. (Credit: Hector Amezcua/The Associated Press)

Northern California communities that were inundated with massive flooding over the weekend could experience more precipitation in the coming days.

It is not clear how much this storm will affect drought conditions that have gripped California, which marked the start of the driest year on record in 2022 and ended with flooded roads and swollen rivers.

“It appears that an early forecast of precipitation for a midweek storm may have about 2 to 3 inches possible in the Central Valley,” the Sacramento Bureau of Meteorological Services said.

An atmospheric river—a long, narrow region in the atmosphere that can hold moisture for thousands of miles—fueled a parade of storms over the weekend, bringing record rainfall and bailing out water.

At least two people have died, authorities said, one found inside a submerged car in Sacramento County and a 72-year-old man who crashed into a fallen tree in Santa Cruz Park.

Now, another river in the atmosphere could cause heavy rain and more flooding Wednesday to northern and central California, including the Bay Area.

The National Weather Service in San Francisco said this upcoming storm “looks like it’s going to lead to dangerous situations.”

The authorities urged residents to avoid driving in standing water.

Interstate 99 remains closed in between@employeeand Grant Line Road south@employeeBecause of the flooding of the Kossumnes River. The road will not be opened until the waters recede, which is expected sometime tomorrow afternoon.@employee⁩ ⁦ pic.twitter.com/TjFo670tul

—Caltrans District 3 (@CaltransDist3) January 1, 2023

Flooding from the Kusumnis River has forced the closure of Interstate 99 south of Elk Grove in Sacramento County, the California Department of Transportation reported Sunday. Its website said SR 99 is one of the busiest lanes in the state and of commercial importance.

In recent days, “dozens and dozens” of people have been rescued, Capt. Chris Chambers of the Kusumness Fire Department told CNN affiliate KCRA. Aerial photos of the station showed cars submerged in water up to the door handles.