A major storm swept into Southern California on Wednesday, bringing rain to most of the region and some snow at higher elevations as many prepared to leave town for Thanksgiving.
Heavier rain began pounding Los Angeles County after dawn, prompting the National Weather Service to issue a flood advisory for the area. It was extended once before expiring at 11:15 a.m.
A flood advisory was in effect in Ventura County earlier in the morning, as several areas received more than a half-inch rain of rain by 8 a.m., according to the weather service.
In the Malibu area, heavy shower were impacting burn-scarred hillsides from last year's Woolsey Fire, NWS tweeted, The agency warned of possible mudslides and falling rocks along the Pacific Coast Highway during the storm.
Other recent burn areas -- including the Saddleridge, Tick and Getty fires -- are also at risk of mud and debris flows, forecasters said.
Scattered showers and isolated thunderstorms are expected to continue through the afternoon, according to the weather service.
The "big winter storm" will likely linger through Friday, but the bulk of the rain will fall Wednesday through Thanksgiving night, according to NWS meteorologist Dan Gregoria.
Widespread rain is expected Wednesday, with most areas of Southern California receiving 1 to 3 inches, he said. Desert areas will get less, about a half-inch to an inch.
Some foothills area may be drenched with as much as 4 inches of rain, according to NWS.
The storm is also predicted to bring significant snowfall to mountain areas -- about 1 to 2 feet above elevations of 5,500 feet, Gregoria said.
By Friday, snow levels will drop 3,000 feet, although little accumulation is anticipated.
The weather service warned of hazardous driving conditions, particularly in mountain areas where snow is forecast. Those traveling to the mountains should bring chains, Caltrans advised.
Areas where chains are required can be found at quickmap.dot.ca.gov.
Snow has already started falling in the Grapevine area of the 5 Freeway, which could be shut down if conditions become unsafe, according to the California Highway Patrol.
"Be prepared for the worst. It's going to be a heavy travel day over the Grapevine," CHP Officer Rich Anthes said.
Snow is expected in most mountain passes, including the 15 Freeway through the Cajon Pass, according to Gregoria.
In addition to possible road closures, forecasters warned the storm could result in significant flight delays on one of the busiest travel days of the year.
“It’s going to impact travel during the peak holiday period here this Thanksgiving," Gregoria said.