Rain was sweeping toward Los Angeles today, timed to arrive just after noon, and snow was predicted to bedevil Interstate 5 over the Grapevine tonight.
A cold weather front sweeping in from the North Pacific threatened to drop temperatures by 10-20 degrees Sunday.
Also it portended snow as low as 3,000 feet, high winds to the deserts and a brief period of afternoon rain in the Los Angeles-area coastal flatlands.
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As of midmorning, the rain front had arrived at Santa Barbara, where about a third of an inch of rain fell in the mountains.
The front was expected to hit Ventura at 11 a.m. and Los Angeles at 1 p.m. The forecast called for a brief period of light rain, although the instability of the cold air in the front hitting L.A.'s warm atmosphere could trigger thunderstorms and localized heavy rain, the NWS said.
More precipitation — up to a half inch — was predicted for the mountains north of Los Angeles, mostly in the form of snow.
"Snow levels will drop significantly and quickly tonight, as cold air pours into the region behind the front, falling to between 3,000-3,500 feet by Monday morning,'' an NWS summary said.
Winter weather advisories were posted for tonight on the northern slopes of the San Gabriel Mountains of Southern California.
Two inches of snow was held possible on the Grapevine, where Interstate 5 crests just above 4,100 above sea level, 55 miles north of Los Angeles.
State Route 14's summit near Acton appeared to be possibly just at the snow level, which meant iffy conditions Monday morning for commuters in and out of the Antelope Valley.
But strong and gusty winds were forecast for the High Desert and canyons north of L.A. In fact, the NWS was predicting damaging winds tonight as trees, weakened by the drought, shed limbs.
A lull in the winds was predicted for midday Monday, but another surge in winds was predicted to hit Monday evening.