A cold Pacific storm is expected to start dousing the Southland Friday in time for the morning commute and make traveling difficult on Interstate 5 in the area of the Grapevine.
The storm - the second this week - will approach the Central Coast from the ocean today, then head south, spread into Santa Barbara and Ventura counties tonight and then into L.A. County, bringing rain and snow Friday, according to the the National Weather Service.
"The early-morning commute on Friday will likely be wet across the entire region," the NWS warned in an advisory. "Commuters should plan extra time to reach their destinations."
There is a slight chance of thunderstorms Friday. Any that develop could
unleash downpours packing small hail, NWS forecasters said.
The storm is expected to generate between a half-inch and an inch of rain in coastal and valley areas, and between one and two inches in the foothills and mountains, they said.
The snow level will be between 4,500 and 5,000 feet tonight, dropping to between 3,500 and 4,500 feet by late Friday, according to an NWS advisory.
Between eight and 14 inches of snow is expected, especially above 5,500 feet,
"Some snowfall can also be expected along Interstate 5 over The Grapevine on Friday evening, which could hamper travel," according to the advisory. "The snowfall, along with gusty winds, will cause hazardous wintry driving conditions with poor visibility and snow-covered roads."
A winter storm warning will go into force in the Los Angeles and Ventura
county portions of the San Gabriel Mountains at midnight tonight and remain
in effect until 3 a.m. Saturday.
In the meantime, an "increasing southwesterly flow" ahead of the storm
will generate gusty winds in the Antelope Valley today, according to an NWS
"The strongest winds are expected in the foothills and across western portions of the valley. Winds may decrease for a while tonight, but even stronger winds are possible Friday," it said.
The storm will not greatly alter temperatures. Highs mostly in the low 60s are forecast today amid partly cloudy skies. Temperatures will dip only slightly during Friday's rain and rise slightly when sunny skies return Saturday. But a warming trend will get under way Sunday.