Rain may douse the Southland beginning Wednesday afternoon, and snow will hamper travel through mountain passes Thursday and Friday as one weather system slides into the region, quickly followed by another, forecasters said.
The first of the two systems is a weak cold front expected to bring a low volume of rain to Los Angeles County this afternoon, according to the National Weather Service.
The snow level Wednesday is expected to range between 4,500 and 5,500 feet, with accumulation of an inch or two possible above 6,000 feet, falling to between 4,000 and 5,000 feet tonight, according to a Weather Service advisory.
A colder low-pressure system is expected to hit the Southland late Thursday, generating showers and possibly thunderstorms accompanied by small hail Thursday night and Friday, it said.
"The main impact with the Friday storm will likely be low snow levels, generally in the 3,000-4000-foot range," according to the advisory, which said there is the potential for six-10 inches of snow above 5,000 feet and one to three inches over mountain passes.
"The low snow level could create snow impacts along some our heavily traveled corridors, including Interstate 5 near The Grapevine, Highway 14 through Soledad Canyon, Highway 138 in the Antelope Valley and Highway 33 in the Ventura County mountains."
Weather Service forecasters urged anyone planning to travel over mountain roads to first check on conditions and carry tire chains, extra food and extra clothing.
Highs today will be 42 on Mount Wilson; 53 in Saugus; 56 in Avalon, San Gabriel and at LAX; 57 in Pasadena, Burbank, and Long Beach; 58 in Newport Beach, Palmdale and Lancaster; and Woodland Hills; and 59 in Anaheim.
Wet weather will last through Friday, with dry weather and a warming trend expected Saturday.