A Pacific storm system will bring rain and snow to Southern California today, along with strong winds, but the foul weather will end Wednesday, National Weather Service forecasters said.
Light showers began developing across San Luis Obispo County late Monday evening, then spread southeast across the area on a trajectory that will put them in the Los Angeles basin this afternoon and evening, according to the NWS.
Showers will continue in Los Angeles County this evening, and a slight chance of showers will linger over northern and eastern mountain slopes late tonight into Wednesday morning, said an NWS statement.
“… By Wednesday afternoon expect skies to begin clearing and all precipitation to end,” it said.
The snow level will fall from 5,500 to 5,000 feet by this afternoon, then to near 4,500 feet by late tonight, but by then only light showers are expected, along with snow flurries and little accumulation, the statement added.
Between two and four inches of snow are expected above 5,000 feet, although up to six inches is possible in some spots, forecasters said. Nonetheless, no weather-related difficulties or road closures are expected in the Interstate 5 Corridor, they said.
Gusty southwest winds will also lash the region. The strongest will be in the San Gabriel Mountains and the Antelope Valley, where gusts of between 40 and 50 miles per hour will be common, NWS forecasters said. A wind advisory will be in effect from noon until 9 p.m. today in the San Gabriel Mountains and the Antelope Valley.
Total rainfall amounts resulting from this late-season weather system out of the Gulf of Alaska are expected to be between a quarter-inch and a half- inch in Los Angeles and Ventura counties, half the volume expected in San Luis Obispo and Santa Barbara counties, although up to one inch of rain may fall in the mountains and foothills, and between a quarter-inch and a third of an inch of rain per hour could come down when the rainfall reaches a peak, according to the NWS.
“This storm should bring localized ponding of water on low-lying streets and highways due to clogged drains,” warned an NWS statement.’
“Wet oil-slicked roads due to the first significant rainfall in a while will impact the morning and afternoon commutes” today, it added.
The threat of mud and debris flows over slopes denuded by wildfire “is low,” although it should be monitored, forecasters said.
In Glendora, where residents near the Colby Fire burn area are constantly on the lookout for rain that could generate mudslides, city officials raised the alert level even though no problems are anticipated. The Yellow alert level calls for residents to remove vehicles and other objects from roadways to ensure emergency crews can access the hillsides and to protect them from any potential mud and debris flows.
The NWS forecast highs today of 44 on Mount Wilson; 56 in Palmdale; 57 in Lancaster; 58 in Saugus; 59 in Avalon; 60 in Burbank and Woodland Hills; 61 in San Clemente; 62 in Pasadena and Laguna Beach; 63 at LAX and in San Gabriel; 64 in downtown L.A., Anaheim and Newport Beach; 65 in Long Beach and Fullerton; 66 in Yorba Linda; and 67 in Irvine and Mission Viejo.
Sunny skies will return to the Los Angeles area Wednesday, and temperatures will be a few degrees higher — two or three in several communities.