A fast-moving cold front was expected to bring snow and strong winds to California's mountains and deserts on Christmas Eve and Christmas Day, a potential gift for the drought-wracked state that could interfere with holiday travel plans, the National Weather Service said.
The storm bearing down on the state Wednesday was forecast to deliver snow at elevations above 4,000 feet in the Sierra Nevada and the mountains in Southern California. Sierra passes could get between three and six inches of snow, with up to 10 inches possible on the highest ridges by morning, said Brooke Bingaman, a meteorologist with the weather service in Sacramento.
Forecasters warned that drivers might experience travel delays Wednesday afternoon and evening on Interstate 80, the main east-west corridor in Northern California, and on the Grapevine, the high-altitude section of Interstate 5 between Los Angeles and the southern San Joaquin Valley, where a winter weather advisory was to go into effect at 3 a.m. Thursday.
Chain controls will be in effect as needed through the evening on I-80, said Dave Wood, an area superintendent for CalTrans who is based in Kingvale. The controls should be lifted by Christmas morning if the storm blows out of the area late Wednesday night as expected.
In Southern California, where revelers from Los Angeles to San Diego enjoyed a second day of unseasonably warm weather in the 70s, forecasters said cold air spilling in behind the storm front was expected to produce an abrupt temperature change and high winds that could continue to make travel difficult on Thursday.
Los Angeles International Airport may get significant, rare cross-winds, and gusts up to 65 mph were possible through mountain passes of Santa Barbara, Ventura and Los Angeles counties, the weather service said. Boaters were advised to prepare for gale-force winds off-shore.
The weather caused brief flight delays on Wednesday at San Francisco International Airport, where air traffic controllers slowed the arrival of incoming flights because of fog and low clouds. Few travelers were inconvenienced because the majority left for their holiday destinations on Tuesday, airport duty manager Larry Mares said.
Clear weather was expected to return on Friday and stay for the weekend, providing ideal holiday conditions for Sierra ski resorts that have weathered three years of relatively dry winters.
"With these early storms, they really get people into the ski mode,'' said Thea Hardy, a spokeswoman for Sierra-at-Tahoe near Echo Summit, about 15 miles from South Lake Tahoe. "They start seeing early storms, and it gets people in the winter spirit.''
The resort already has about 3 feet of snow at its 8,800-foot summit and has plans for Santa Claus to ski and snowboard all day on Christmas.
Rainfall totals from the storm were expected to be modest. The National Weather Service predicts about a tenth of an inch of rain falling in the San Francisco Bay Area and Sacramento Valley with up to a quarter inch farther north in the Redding and Red Bluff area.
State water managers are scheduled to conduct their first winter survey of the Sierra snowpack on Tuesday. Melting snow from the snowpack usually supplies about a third of the state's water, and officials say it will take a series of storms producing above-average snow and rain to make up for three consecutive years of extreme drought.