Southern California drenched by heavy rain, flooding some streets

A cold system continues to make its way across Southern California, bringing more rain and the potential of isolated thunderstorms. 

All eyes were on the Grapevine as snow flurries were falling on Monday morning. Caltrans reported at 3:50 a.m. that traffic was being escorted along the Grapevine due to snow. 

The National Weather Service said snow levels stayed around 3,500 feet and recommend commuters avoid the Tejon Pass until the storm tapered off by Monday evening. 

On Sunday, steady rain fell on the Southland, causing minor flooding, mud and debris flows closing some roads. In Burbank and Lancaster, record rainfall was reported. Hollywood Burbank Airport reported 1.21 inches of rain, breaking a record of 1.09 inches set for the day in 1996. Lancaster reported 0.46 inches of rain, breaking a record of 0.16 inches set for the day in 1993.

The Los Angeles County Department of Public Works reported Sunday morning that Lake Hughes Road, between Pine Canyon and Dry Gulch roads in Lake Hughes, was closed due to mud and debris on the roadway. The department was asking the public to avoid the area and use alternate routes.

The Pomona Police Department reported flooding at the underpass at First Street, with several streets in the area either closed or affected by flooding, including South Reservoir Street, South Towne Avenue, East End Street, Garey Avenue and White Avenue.

Heavy rain was falling in the northern San Fernando Valley, where the California Highway Patrol was at the scene of a big-rig crash on northbound Interstate 5 at Sheldon Street in the Sun Valley area.

The vehicles involved in the crash were cleared around noon, but both sides of the freeway were flooded as of 12:30 p.m. The three right lanes were blocked on the northbound side with the HOV and left lane open, and the three right lanes were blocked on the southbound side with the left lane open. Caltrans had its pumps on the scene trying to clear the water.

In Orange, firefighters and paramedics pulled a man from the river during a swift water rescue in the area of the Santa Ana River and Garden Grove Boulevard. He was taken to a hospital for follow-up care.

RELATED: VIDEO: Firefighters rescue man swept away in Santa Ana River

"Received significant rainfall over our mountains last night and we are starting to see a response in our local main stem rivers. Not enough to reach monitor or flood stage, but finally seeing some flow," the National Weather Service's Los Angeles office tweeted at 8:33 a.m.

Shortly after 9 a.m., the NWS said Doppler radar indicated heavy rain due to thunderstorms in south Orange County, and minor flooding expected to begin in Irvine, Mission Viejo, Rancho Santa Margarita, San Clemente, Laguna Beach, Dana Point and Laguna Niguel.

The Angeles National Forest said roads in the forest might be very slick and/or closed due to rain or snow. Tire or snow chain requirements could be in effect.

Forecasters said heavy downpours and small hail were possible in some areas through Sunday evening.

The Los Angeles County mountains were predicted to see rainfall rates of 1/2- to 3/4-inch per hour. Those rates prompted the NWS to issue a flash flood watch for the Fish Fire and Lake Fire burn areas, which expired shortly before noon Sunday.

The weather was causing some power outages as well. The Los Angeles Department of Water and Power tweeted at 8:46 a.m. that crews were working to restore power to affected customers as quickly and safely as possible, while working in challenging conditions.

By Sunday morning, 4.73 inches of rain had fallen at Stunt Ranch in the Santa Monica Mountains. The snow level remained high through Sunday morning, but could drop later in the day to as low as 3,000 feet, meaning "snow could accumulate on portions of I-5 near the Grapevine. This could cause major travel disruptions at the end of the weekend," according to the NWS.

Wind advisories were in place Saturday night and Sunday morning in the greater LA area and the valleys, but they expired by late Sunday morning as wind speed diminished. A wind advisory remained in place until 6 p.m. in Orange County.

The Los Angeles County Department of Public Health cautioned those planning to visit county beaches to be careful of swimming, surfing and playing in ocean waters due to possible contamination caused by storm drain discharge.

RELATED: Ocean water quality advisory in effect for all LA County beaches through Wednesday morning

The advisory was in effect until 7:30 a.m. Wednesday.

Ocean and bay recreational waters, especially near discharging storm drains, creeks and rivers, can be contaminated with bacteria, chemicals, debris, trash and other public health hazards from city streets and mountain areas after rainfall. Individuals who enter the water in these areas could become ill.

The storm is expected to pass through the area by Sunday night. Some lingering showers will be possible Monday morning, primarily in mountain areas, forecasters said.