LOS ANGELES -- Authorities were keeping a wary eye Friday on fire-scarred Southern California hillsides after a storm brought flooding fears and prompted evacuation orders for hundreds of homes, some of which were later downgraded to voluntary.

Thursday's second storm in a week dropped record-breaking rains on downtown Los Angeles, jammed major roads and sent an airliner skidding off a runway, but no major injuries were reported.

Evacuations were ordered for areas of Orange and Riverside counties ravaged by a summer wildfire. Black, surging torrents choked with downed trees and mud swept down channels near homes and in one case swept across a bridge and took out a guardrail. Other areas saw foot-deep mud or water.

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No homes were seriously damaged. Even though the storm eased by nightfall, evacuation orders for hundreds of homes in Trabuco Canyon in the Santa Ana Mountains south of Los Angeles and for a few neighborhoods in the Lake Elsinore area east of Los Angeles remained in place overnight.

Other Lake Elsinore areas had their mandatory evacuation orders downgraded to voluntary evacuation warnings late Thursday night, although fire officials said there was still a potential for dangerous conditions and urged residents to remain vigilant.

Also in Lake Elsinore, firefighters worked into the night lining a street with sandbags to protect homes.

A mudslide shut down the Pacific Coast Highway and surrounding roads in and around Malibu neighborhoods charred by another fire last month that destroyed hundreds of homes.

Car stuck in morning mudflow along PCH near #Mulholland in #Malibu, driver was ok and this mudflow now almost full cleared @CBSLA pic.twitter.com/eU0EqaUxvS — Kara Finnstrom (@KaraFinnstrom) December 6, 2018

A small boulder was spotted in the center of an area road, CBS Los Angeles reported:

Caltrans is still cleaning mud from the SB I-5 truck lanes at SR-14. The lanes remained closed at this time. pic.twitter.com/3zHArOLNhV — Caltrans District 7 (@CaltransDist7) December 7, 2018

Kirby Kotler and his neighbors spent days before the storm stacking 18,000 sandbags behind their homes along the highway. But when heavy rains arrived, mud, water and rocks blasted through the bags and across their properties.

Kotler, who wielded water hoses to beat back the flames in November, used a tractor to keep the debris from entering his home.

"Saving my house once again," said Kotler, 57, a lifelong Malibu resident. "I'm more than a little concerned. If we get another blast of heavy rain there'll be no stopping the hill from coming down."

At Hollywood Burbank Airport, about 15 miles north of downtown Los Angeles, nobody was hurt when a Southwest Airlines plane from Oakland skidded off a wet runway as it landed. The plane came to a stop in a graded area designed to slow aircraft that overshoot the runway, the Federal Aviation Administration said.

Los Angeles and the rest of Southern California sorely need rainfall. Virtually the entire region is experiencing drought conditions, with portions of Los Angeles and Ventura counties and areas along the Mexican border in extreme drought.

The storm provided a big boost in and around Los Angeles. The downtown area set a new rainfall record for the day with 1.9 inches, nearly double the previous mark set in 1997, the National Weather Service reported. Normal monthly rainfall for December is only a bit more - 2.33 inches.

Elsewhere, fire crews had to rescue a man from the flood-swollen Los Angeles River, a concrete flood control channel, and helped motorists to safety in several areas where cars became stuck in flooded intersections.

While rain caused numerous accidents and backups on L.A.-area freeways, heavy snow forced the closure of Interstate 5 in the Grapevine area between Los Angeles and the San Joaquin Valley. The hours-long shutdown along the key north-south route caused backups for miles.

Motorists were urged to use caution on mountain passes, where up to 6 feet of snow was predicted at higher elevations.

Forecasters said the end of the storm would be followed by a ridge of high pressure that will bring dry and warm conditions to the area through the weekend, but another storm system could move in early next week.