Winter Storm Warning for 10 States as California Floods Rage

Winter storm warnings are in place for parts of 10 states as a powerful atmospheric river from the Pacific Ocean continues to move east after making landfall in California on Sunday.

The National Weather Service (NWS) issued alerts for Alaska, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Utah and Wyoming on Wednesday, warning of heavy snow, high winds and the continued threat of flooding.

It comes as heavy rain and areas of flash flooding persist in California, which have caused mudslides and saw trapped residents clinging to trees. The flooding prompted California Governor Gavin Newsom to declare a state of emergency for several counties in Southern California on Sunday.

As of Wednesday, there had been seven storm-related deaths in the state, the Associated Press reported, citing officials. As of 5:30 a.m. ET on Wednesday, nearly 75,000 homes in California remained without power due to downed electricity lines, according to figures compiled by PowerOutage.

The state already faced several inches of rainfall last week after a "plume of moisture" from the subtropics made its way eastward on Thursday and Friday. The extended storm period has led to historic levels of precipitation.

In its latest forecast, the NWS said thunderstorms were likely to remain for the West Coast and desert southwest as moisture continues to flow eastward, with up to a foot of snow across the Sierra Nevada mountain range. The heaviest amounts of snow will fall in the Four Corners region, the meteorological agency said.

It noted that "while the influx of anomalously high moisture associated with this past weekend's atmospheric river has ended, moderate to locally heavy rainfall on top of the very wet antecedent conditions may still bring a risk for some isolated instances of flooding."

As well as the ongoing impacts on California, as much as 15 inches of snow in mountain regions of Nevada "will create very dangerous avalanche conditions, hazardous to anyone near deep and unstable snowpack," the NWS warned. Wind gusts could reach 45 miles an hour.

Up to 20 inches of snow is expected over the White Mountains of Arizona, with high winds reducing visibility. Conditions are set to worsen in higher elevation regions of Utah, where up to four feet of snow could fall.

In northern and western New Mexico, as much as 16 inches of snow is anticipated, with wind gusts of up to 45 miles an hour. Up to 20 inches of snow is expected in western Colorado, where winds could reach 50 miles an hour.

This weather will continue into southern Wyoming, where the Sierra Madre mountain range is predicted to receive as much as two feet of snow and see winds of up to 50 miles an hour.

North central Idaho is set to have up to 15 inches of snow at higher elevations, with seven inches in valleys. Heavy snow is also expected in west-central Montana, where between five inches and a foot of snow is expected to fall.