WRIGHTWOOD, Calif. -- A strong storm system that brought relentless winds, rain and snowfall to California this week was expected to ease Friday, but there was still a risk of high surf along the coast, flash flooding near Los Angeles and avalanches in the Sierra Nevada.

More than 41 million Americans across California, Nevada and Arizona are under flood watches on Wednesday amid a rare, high risk for excessive rainfall and flooding.

A sweeping flood watch stretching more than 800 miles along California’s coast and interior plains is in effect this week atmospheric rivers move through.

Residents of Los Angeles spent the day before Christmas under rain showers and winds of around 40 mph, while the New England area braces for heavy snow later in the week.

The Christmas rain storm expected to washout California over the next few days is already rearing it’s ugly head — as a debris flow ripped through the mountain town of Wrightwood in San Bernardino County early Wednesday.

Officials in Los Angeles and surrounding counties warned that the giant holiday storm could trigger "widespread flash flooding."

The winter storm brought heavy rain, flooding, and road closures across California. Officials evacuated people, closed major roads, and declared a state of emergency., US News, Times Now