A satellite image shows water vapor above the Western U.S. on Dec. 12, 2012.

A satellite image shows water vapor above the Western U.S. on Dec. 12, 2012. (National Weather Service / December 12, 2012)

A storm barreling in from the Gulf of Alaska is expected to douse Southern California with rain and snow beginning Wednesday, prompting several mountain road closures.

Between a quarter and a half-inch of rain could drench the coast and valleys, while the mountains could get as much as an inch, National Weather Service meteorologist Curt Kaplan told the L.A. Times.

By Thursday, snow is expected to blanket the mountains as low as 3,500 feet.

L.A. County Public Works officials are closing segments of the Angeles Forest Highway and Upper Big Tujunga Canyon Road starting at 10 p.m. Wednesday.

Angeles Forest Highway will be closed from Aliso Canyon Road to Upper Big Tujunga Canyon Road, which will be closed from that point to Angeles Crest Highway.

Local access will not be permitted until the storm system passes and the roads have been inspected, officials warned.

A 24-hour winter weather advisory for the mountains that begins Wednesday at 4 p.m. warns of breezy winds with gusts up to 40 mph.

Temperatures in the region will be below normal -- in the high 50s to mid-60s though the weekend. Forecasters anticipate the possibility of rain lingering through Tuesday.

-- Los Angeles Times staff writers, and Daniel Siegal, Times Community News