A strong, fast-moving cold front is expected to bring rain to most of Southern California and snow to area mountains Friday into Saturday.
The storm should arrive in the region by Friday night, according to the National Weather Service.
A winter storm warning has been issued for the mountains of Los Angeles, Riverside, San Bernardino and Ventura counties.
Flash floods are a possibility in wildfire burn areas, including the Blue Cut and Pilot fires in San Bernardino County, and the Sand, Fish, Sage and Springs fires in L.A. and Ventura counties.
Strong winds — with gusts of 50 to 60 mph — will also sweep through the region till Saturday night.
A phenomenon known as the "Palmdale wave" could bring damaging winds to Antelope Valley foothills Friday afternoon and evening, the weather service tweeted.
By the time the front passes early Saturday, snow levels could drop as low as 3,000 feet in the local mountains.
The 5 Freeway through the Grapevine and the 15 Freeway in the Cajon Pass could both see snow, and other mountain roads will likely be affected.
Snow accumulations of 8 to 16 inches are expected above 6,500 feet, with reduced accumulations at lower elevations.
The storm, coming down from the Gulf of Alaska, is the second and stronger of two storms to hit Southern California this week. The earlier, warmer storm hit Wednesday through Thursday morning, with rainfall totals of up to 1.37 inches in the San Gabriel Mountains.