I-5 going over the Grapevine is expected to be a mess Thursday night into Saturday morning.
LOS ANGELES -- A blizzard warning by the National Weather Service is the first such alert issued for the Southern California mountains since 1989, the agency said.
The warning is scheduled to take effect at 4 a.m. Friday and will last until 4 p.m. Saturday. The National Weather Service predicts from 2 to 5 feet of snow could accumulate in the mountains above 4,000 feet, falling even as heavy winds gust up to 75 mph.
The agency initially said the warning was the first one in recorded history for the area. However, a New York-based meteorologist later discovered the text of a blizzard warning that was issued by the National Weather Service Los Angeles on Feb. 4, 1989.
"Looks like it was issued after reports came in. Even if this is not our 1st, this is a dangerous storm. Do not travel in the mountains" on Friday and Saturday, the agency said on Twitter.
Snow is expected to fall as low as 1,000 to 1,500 feet, meaning areas like Santa Clarita and lower-lying areas of the Inland Empire will see a rare coat of powder.
Below that, at elevations of 2,000 to 4,000 feet, about 6-12 inches of snow are expected.
Visibility at that time is expected to be very low and travel is not advised through those areas.
Passes like the Grapevine and the Cajon Pass are likely to also see dangerous driving conditions. Drivers are advised to bring chains and a full tank of gas and be prepared for difficult weather and road closures.
"They're expecting snow to drop as low as 1,000 feet," said Mark Bishoff with Caltrans. "The top of the Grapevine is a little over 4,000 feet, so they're expecting it to be impacted by snow."
"If you can stay home, then stay home. That's the best choice that you can make. If you do have to go, then make sure your car is prepped. Make sure the tires are inflated properly, your windshield (wipers) and your headlights are working."
Bishoff added California law requires headlights need to be on when windshield wipers are in use.
He also recommends drivers have a kit with them in their car if they do need to hit the road: a blanket, cellphone, charger, water and snacks.
Powerful, chilly winds were already blowing through sections of the Antelope Valley and Inland Empire by Tuesday afternoon as ominous dark clouds formed on the horizon.
The storm front was sweeping down from the Canadian Rockies and the Yukon, with the leading edge arriving late Tuesday. But the brunt of it will start Thursday, with heavy rain at lower elevations. Some communities can expect to see 3-4 inches of rain by the weekend.
Agencies like Caltrans and the CHP were mobilizing Tuesday for expected road closures and preparing to help drivers stuck on mountain roads.
"It's gonna be a safety concern," said Officer Monique Mischeaux with the CHP. "If it's not safe for the motoring public to use those highways, we will shut them down. That's why we want people to prepare in advance."
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