A cold storm out of the Gulf of Alaska will generate three to five hours of steady rain in the southland starting late Thursday afternoon and challenging travel conditions in mountain areas before clearing out, setting the stage for a sunny Friday, followed by a mostly cloudy weekend, forecasters said.
The storm’s greatest impact may be in the San Gabriel Mountains, where a winter weather advisory denoting high winds and tough driving conditions will be in force from 1 p.m. Thursday until 1 p.m. Friday amid a falling snow level and furious winds, they said.
No mud slides or debris flows are expected over slopes previously denuded by wildfires — in L.A., Orange and Riverside counties — because the rainfall at no time is expected to exceed a half-inch per hour, said meteorologist Curt Kaplan at the National Weather Service’s Oxnard station.
In Orange County, the “weak” storm’s main band is expected between 11 p.m. Thursday and 4 a.m. Friday, producing “light showers” this evening amid southwest winds of between 15 and 18 miles per hour, said meteorologist Miguel Miller at the NWS station in San Diego, where Orange County conditions are forecast and monitored. The storm will clear out by sunrise, he said.
In L.A. County’s San Gabriel Mountains, the snow level will fall to between 4,500 and 5,500 feet during daytime hours, then to between 3,500 and 4,500 feet by late Thursday evening, the NWS said. Between four and eight inches of snow is expected to accumulate above 5,500 feet while an accumulation of two to four inches is anticipated between 4,500 and 5,500 feet, and two inches — a dusting — is expected between 3,500 and 4,500 feet, it said.
At the same time, south to southwest winds of 25 to 35 mph gusting to up to 50 mph will sweep across the San Gabriels, and road closures may be required on Interstate 5 through the Grapevine and Ventura County’s Highway 33, the NWS said.
“Slow down and use caution while traveling,” urged an NWS statement.
The Antelope Valley will also be windy, with the weather service forecasting winds 20 to 35 mph, with gusts of up to 50 mph. The strongest winds will be in the foothills.
“Gusty winds could blow around unsecured objects. Tree limbs could be blown down. Blowing dust could locally reduce visibility in the desert at times Thursday afternoon in advance of the rain,” warned an NWS statement.
“Travel may become hazardous for high-profile vehicles traveling along Highways 14 (the Antelope Valley Freeway) and 138 (Pearblossom Highway) in the Antelope Valley,” it added.
Between a quarter-inch and three quarter of an inch of rain are expected along the L.A. County coast and in the county’s valleys, and between three-quarters and an inch-and-a-half in the mountains and foothills, according to the NWS. Similar conditions are expected in Orange County Thursday, with a quarter inch of rain near the coast starting late in the day, and between a half-inch and an inch in the Santa Ana Mountains.
The NWS forecast rain in L.A. County Thursday and highs of 43 on Mount Wilson; 55 in Lancaster; 56 in Palmdale; 57 in Burbank; 58 in Woodland Hills; 59 in Pasadena, San Gabriel, Long Beach and at LAX; and 61 in Downtown L.A. Temperatures will rise up to six degrees Friday amid sunny skies and up to six more Saturday under mostly cloudy skies.
Mostly cloudy skies were forecast in Orange County Thursday, along with highs of 46 on Santiago Peak; 51 on Oetega Highway at 2,600 feet; 55 in Fremont Canyon; 57 in Laguna Beach; 58 in Trabuco Canyon and Yorba Linda; 59 in San Clemente and Anaheim; 60 in Mission Viejo, Newport Beach and Fullerton; and 62 in Ievine. Highs will be up to five degrees higher amid sunny skies Friday and up to seven higher under partly cloudy skies Saturday.
>> Want to read more stories like this? Get our Free Daily Newsletters Here!Follow us: