High winds will begin lashing the Southland tonight and snow will start falling in the San Gabriel Mountains, forecasters said this morning in heralding a wind-swept, partially white Christmas.
A high wind warning signifying an expectation of 58-mile-per-hour winds will be in effect from 10 p.m. today until noon Thursday in the San Gabriel mountains in Los Angeles and Ventura counties, the National Weather Service said.
North winds blowing at sustained speeds of 30 to 45 miles per hour and gusting at 65 mph will develop in the mountains late this evening, according to NWS forecasters.
“Winds this strong can make driving difficult, especially for high- profile vehicles,” said an NWS statement, warning motorists of sudden, gusty crosswinds.
The winds lashing the San Gabriels may make driving difficult on the Glendale (2) and Antelope Valley (14) freeways and Interstate 5, according to the statement, which noted that high winds can down tree limbs and trigger power outages.
In the Santa Monica Mountains Recreational area and the San Fernando and Santa Clarita valleys, a wind advisory, which is less serious than a high wind warning, will be in force from 1 a.m. Thursday until noon. North winds of 20-30 mph accompanied by 50-mph gusts will develop just after midnight and persist through noon in all three areas, forecasters said.
In the Antelope Valley, where 20-30-mph winds are expected along with 50- mph gusts, a wind advisory will be in effect from 10 tonight until 8 Thursday morning, said the NWS. Forecasters urged motorists to beware of crosswinds and blowing dust and said the western tier of the Antelope Valley would experience the fiercest winds.
Also expected on Christmas Day is snow, which may begin falling late tonight in the form of showers along north slopes, according to forecasters. They said the snow level will drop to between 4,000 and 5,000 feet by dawn on Christmas Day, and snow accumulation of between 1 and 3 inches is possible near The Grapevine.
The NWS issued a winter weather advisory for the San Gabriels, effective from 3 o’clock Thursday morning until 1 in the afternoon.
“Mountain travel, especially through the Interstate 5 corridor, will be difficult due to a combination of snow, blowing snow and strong winds,” according to an NWS statement, which warned that visibility would fall to near zero at times.
NWS forecasters urged motorists setting out on mountain roads to use caution and pack an emergency kit that includes a flashlight, food, water, extra clothes, blankets, and tire chains.
An NWS forecast indicated today’s temperatures, under sunny skies, would be warm but much cooler Thursday amid partly cloudy conditions in Los Angeles County but sunny skies in much of Orange County.
The weather service forecast highs of 63 today, 47 Thursday on Mount Wilson; 63 today, 49 Thursday in Lancaster; 64 today, 50 Thursday in Palmdale; 67 today, 62 Thursday in San Clemente; 69 today, 62 Thursday in Laguna Beach; 69 today, 63 Thursday in Newport Beach; 71 today, 56 Thursday in Saugus; 71 today, 62 Thursday at LAX; 72 today, 60 Thursday in Mission Viejo; 72 today, 62 Thursday in Fullerton and Anaheim; 72 today 63 Thursday in Avalon; 73 today, 61 Thursday in Yorba Linda and Irvine; 74 today, 64 Thursday in Long Beach and downtown L.A.; 74 today, 61 Thursday in San Gabriel; and 74 today, 62 Thursday in Pasadena, Burbank and Woodland Hills.