A cold storm out of the Gulf of Alaska will generate light rain in the Southland today and on Christmas Day, along with low temperatures, snow at low elevations, high surf and fierce winds, forecasters said.
The storm — one of several to slide across California this week — will produce generally light rain today and perhaps on Christmas morning, though showers will persist in mountain areas Friday afternoon, a National Weather Service statement said.
A tenth of an inch of rain or less is expected in Los Angeles and Ventura counties as a result of the latest weather system, which could produce up to a quarter-inch along the Central Coast to the north, it said.
In the San Gabriel mountains, the snow level will start off at between 5,000 and 6,000 feet, dropping to around 3,000 feet by Christmas morning, the NWS said. Snow could accumulate on Interstate 5, especially from Gorman to the Kern County line, and icy road conditions could develop from late tonight until Friday morning, NWS forecasters said.
Additionally, 20-30-mph winds gusting to 45 mph could unleash blowing snow, reducing roadside visibility to less than a half mile, they said.
The prospect of snow and plowing snow prompted the NWS to issue a winter weather advisory this morning for the San Gabriels in L.A. and Ventura County. It will be in effect from 10 tonight until noon Friday.
The wind is expected to be a big part of the Christmas weekend, with gusty northerly winds starting tonight but possibly turning into Santa Ana Winds Friday night and persisting through Saturday night, according to the NWS.
Damaging wind gusts of 60 miles per hour are possible in the mountains and foothills, and gusts of more than 40 mph could extend from the mountains all the way to the Southland coast on Saturday, it said.
High wind watches, denoting an expectation of 58-mph gusts, may be issued later today “to cover this potentially high wind event”, a statement said.
“The combination of gusty winds, wet roads and holiday traffic will lead to hazardous driving conditions Thursday night into Friday,” it said, adding that snow and blowing snow could sharply reduce visibility above 3,500 feet, including on Interstate 5 near The Grapevine, it said.
Forecasters said the wind would exacerbate already low temperatures, resulting in several hours of subfreezing temperatures in wind-prone valleys in L.A. and Ventura counties, the statement said, warning that children, the elderly and the homeless are particularly vulnerable in such conditions.
Along the coast, a coastal flood advisory will be in effect until 10 Christmas morning in both L.A. and Orange counties, reflecting an expectation of minor flooding resulting from elevated surf of 4-6 feet combined with high tides. The high surf will also create a “moderate to high risk” of rip currents, creating drowning risks, the NWS said.
All in all, “cold and unsettled weather” is expected, according to the NWS.
The NWS forecast partly cloudy skies today and highs in L.A. County of 51 on Mount Wilson and in Palmdale and Lancaster; 59 in Saugus; 60 in Avalon and Burbank; 61 in Long Beach; and 62 at LAX and in Pasadena, San Gabriel and Woodland Hills.
In Orange County, the NWS forecast highs of 61 in Mission Viejo; 62 in Newport Beach, Laguna Beach, Irvine and San Clemente; 63 in Yorba Linda; and 64 in Fullerton and Anaheim.
Friday’s temperatures will be the same as today’s or marginally lower. Saturday’s will be the same as Friday’s but under sunny skies.