Cars are submerged in floodwater after heavy rain moved through the area on Monday in Windsor, California. The San Francisco Bay Area continues to get drenched by powerful atmospheric river events that have brought high winds and flooding rains.

Cars are submerged in floodwater after heavy rain moved through the area on Monday in Windsor, California. The San Francisco Bay Area continues to get drenched by powerful atmospheric river events that have brought high winds and flooding rains. / Getty Images

Another powerful winter storm system is approaching California, where intense downpour has already wreaked havoc on communities earlier this month.

The National Weather Service says California will likely see two major episodes of rain "in quick succession" on Monday and Tuesday. The first downpour is expected to especially pummel the central California coast, which is expected to see up to 3 to 5 inches of rain. The second deluge, on Tuesday, is predicted to mainly unload on southern California.

Heavy rainfall will also likely cause more flooding, dangerous mudslides, power outages and tree damage.

But it's not just rain that's a worry. More than six feet of snow is expected to pile on the Sierra Nevada mountains in northern California up until Wednesday — increasing the risk of avalanches.

This week's storm comes as California is already reeling from a streak of bad storms since Christmas. As of Monday afternoon, more than 137,000 customers were without power, according to utility companies' reports tracked by PowerOutage.US.

"We've got several storms behind us but we've got several storms ahead of us still," Nancy Ward, the director of the California Office of Emergency Services, said in a press conference on Sunday.

About 2,900 people evacuated their homes and 199 were in shelter as of Sunday. President Biden has declared an emergency in California and ordered federal assistance.

This week also marks California's fifth atmospheric river since Christmas. The phenomenon, which meteorologists call "rivers in the sky," can cause intense rainfall and flooding.

A sixth one is expected to reach California later in the week, between Thursday and Saturday, according to Karla Nemeth, director of the California Department of Water Resources.

What to expect in California

The National Weather Service issued a flood advisory for parts of the Sacramento Valley and the surrounding area until 6 p.m. local time. In Wilton, southeast of Sacramento, residents have been asked to evacuate indefinitely due to concerns that rising waters will block off exit routes.

Other parts of northern California, including Santa Cruz, Watsonville and Scotts Valley, are at risk of life-threatening flash flooding on Monday, according to the National Weather Service.

In southern California, forecasters also warned of floods in San Luis Obispo, Santa Barbara and Ventura counties, with rain pouring up to .75 inches per hour.

Many schools, particularly in northern California, are closed in response to the harsh weather, including the entire Sacramento school district, which reported that at least six of its schools had power outages.

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