Southern California will cap off the year with another round of rain and snow as the second of two weekend storms moved through Saturday.
The National Weather Service warned that burn-scarred areas hit by wildfires in recent years could see mudslides and debris flows from the rain.
The storm could bring as much as a half-inch of precipitation across most of Los Angeles and more than an inch in the mountains. Most of the rain will fall between about 3 and 8 p.m., forecasters said, with light showers likely later into the evening.
The latest system was expected to be very cold, promising to lower snow levels to elevations that could make travel difficult into and through mountain ranges.
Late Saturday afternoon, the California Highway Patrol tweeted that two of the northbound lanes on Interstate 5 in Gorman were closed due to snow.
The San Gabriel Mountains will be the hardest-hit with snow, with an accumulation of about 8 to 10 inches expected there.
A flash-flood watch is planned for the burn areas starting at 3 p.m. Saturday.
Winter weather warnings and advisories were posted across Ventura, Los Angeles, Orange and San Diego counties.
A warm low-pressure storm system brought showers to Southern California starting Friday and slowly moved east as the cold weather system moved down the state from the north.
Rainfall amounts were modest Friday, mostly a few tenths of an inch, but nonetheless adding to precipitation accumulations well above normal to date despite continuing drought.
The chilly forecast prompted the Los Angeles County Department of Public Health to extend a cold weather alert for mountainous areas and the Antelope Valley through Wednesday. Temperatures in those areas are expected to dip below 32 degrees.
"Children, the elderly and people with disabilities or special medical needs are especially vulnerable during such cold snaps," county interim health officer Jeffrey Gunzenhauser said in a statement.
California's wet December was a welcome respite amid years of drought.
Downtown Los Angeles has had around 5½ inches of rain since the start of the water year on Oct. 1, more than five times the amount that had fallen to date last year.
Nearly 17.5 percent of California — a chunk of the far north and the coastal strip south to Monterey Bay — is now free of drought indicators but a large swath of the state is still in the grip of the worst levels of dryness, according to this week's U.S. Drought Monitor update, which noted widespread precipitation in the western U.S. since Dec. 22.
Weather was expected to be dry but cloudy for the 128th Rose Parade in Pasadena, which will be held on Jan. 2 due to a never-on-Sunday rule.