Updated

A series of storms will leave southern parts of the Golden State looking quite grey for most of the week, bringing the risk of mudslides in fire-devastated areas in California and heavy snow to mountain areas, according to forecasters.

The National Weather Service's Los Angeles office said Tuesday that periods of heavy rain, high-elevation mountain snow, and gusty winds will remain throughout the region until Friday.

"Heavy rain expected through this evening," the NWS said. "People in and around recent burn areas should listen to local officials if asked to evacuate the areas."

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Los Angeles and Ventura Counties are expected to see between one and a half and three inches of rain, with some areas of the Santa Monica Mountains seeing four inches of rain through Tuesday night.

Mandatory evacuations over mudslide fears

The prolonged rainfall over areas impacted by wildfires in Southern California caused officials to urge residents to pack up and leave due to fears of mudslides.

This photo provided by the California Department of Transportation (CalTrans) shows a skiploader clearing a river of mud that has flowed onto Pacific Coast Highway in Malibu, Calif., Monday, Jan. 14, 2019. (CalTrans via AP)

In Riverside County east of Los Angeles, voluntary evacuations were ordered Monday for a dozen areas around the Holy Fire, which swept through an enormous swath of the Cleveland National Forest and surrounding areas last August.

"People in these zones SHOULD GO NOW. Rainstorms carry the potential for dangerous debris flows that can send mud, boulders and trees crashing down hillsides" with little or no warning, a county statement said.

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In Santa Barbara County on the central coast, evacuation orders were set to take effect at 10 a.m. Tuesday for areas hit by the Sherpa, Whittier and Thomas fires, according to FOX11.

On Monday, the first in the series of storms dumped an inch of rain in Los Angeles area, sparking a mudslide that closed a section of the Pacific Coast Highway just north of Malibu for several hours.

Flooding was reported in Southern California on Monday as the first of a series of storms moved in. (FOX11)

In Encino, located in the San Fernando Valley of Los Angeles, a guest house was pushed off its foundation by a 250-foot-long debris flow from a hillside.

Homeowner Joyce Sachs told FOX11 it's lucky nobody was in the guest house after that property was filled with several feet of debris that knocked it off its foundation.

“My grandson could have been in the guest house and that is totally full of mud,” Sachs said. “He lost everything.”

Geologists who surveyed the hillside believe it's stable, but issued voluntary evacuations for a dozen other homes in the neighborhood.

“Given the amount of saturation we’ve already had today it’s going to continue to get worse on this hill,” Battalion Chief, Andrew Wordon, Los Angeles Fire Department, told FOX11.

Frozen mess for drivers

The same storm that dropped the heavy rainfall made for treacherous driving in higher elevation areas.

Ice and blowing snow shut down the Grapevine, a high pass on Interstate 5, a major route connecting Los Angeles with San Francisco. Dozens of cars and trucks were stranded before the road reopened after nightfall.

This photo provided by the California Department of Transportation shows traffic stopped on Interstate 5 where it has been closed due to snow at Tejon Pass, an area known as the Grapevine, at Gorman in the Tehachapi Mountains of Southern California, Monday, Jan. 14, 2019. (CalTrans via AP)

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Demetrius Moore, a 35-year-old producer for a court TV show in Chicago, told the Associated Press he was in California for a warm-weather winter vacation. Instead, he found himself huddling in his rental car in the mountain town of Gorman.

"I have just over a quarter of a tank," Moore told the AP. "I'm growing concerned. I have water and a little bit of a latte left, no food. I'm just kind of hanging out, hoping for the best and wondering if I'll get out."

This photo provided by KGET-TV shows a CalTrans snow removal vehicle clearing a roadway on Interstate 5 in an area known as the Grapevine, at Gorman in the Tehachapi Mountains of Southern California. (KGET-TV via AP)

Caltrans warned drivers that the forecast for heavy snow this week should be a reminder to drivers to prepare for winter conditions before they go out.

"If you must travel, motorists should take first-aid kits, blankets, flash lights, snacks and water," the agency said.

The Associated Press contributed to this report.