Temperatures plunged into the 30s and low to mid-40s across Southern California Thursday morning, lowering snow levels as a potent winter storm moved into the region.

Light snow fell in areas of Santa Clarita, Simi Valley, La Crescenta, La Cañada Flintridge, Sun Valley, and San Bernardino County, including Fontana and Yucaipa.

Scattered rain showers and hail were more widespread.

In Yucaipa, slick and icy conditions contributed to a 20-car pileup that sent eight people to the hospital overnight.

Six Flags Magic Mountain in Valencia announced it would not open Thursday due to the inclement weather.

“Expect scattered showers to continue through the afternoon,” the National Weather Service tweeted. “(The storm) will bring periods of heavy rain and snow to most of Southwest California Friday into Saturday.”

Blizzard warning

High wind and winter storm warnings have been issued for Los Angeles, San Bernardino, Riverside and Ventura counties. NWS also issued a blizzard warning for mountain areas in Ventura and L.A. counties — the first since 1989 — which takes effect at 4 a.m. Friday and extends through 4 p.m. Saturday.

“We have not experienced blizzard-like conditions in our Southern California mountains since before 2007,” KTLA weatherman Kaj Goldberg said. “So, we’re getting ready for an historic event.”

“Snow accumulations up to 5 feet and wind gusts in excess of 55 mph are expected,” the NWS said on Twitter. “Low snow levels will mean that this could be the largest amount of 24-48 hour snowfall seen in decades for our Ventura and Los Angeles County mountains.”

Caltrans warns nonessential travelers to avoid areas of the San Bernardino County Mountains, like Big Bear, where snow began falling Wednesday with much more ahead.

“We’ll be talking about 1 to 2 inches of snow per hour,” Andrew Tardy, with the National Weather Service, told KTLA. “We’ll be talking about 2 to 3 feet of snow by Saturday evening.”  

Snow levels began to drop from the mountains down to elevated valleys and mountain passes in the L.A. area Thursday morning. Elevations as low as 1,000 feet could see 1 to 6 inches of snow, creating dangerous driving conditions on the 5 Freeway through the Grapevine and elsewhere.

While the north and southbound lanes of the 5 Freeway through the Grapevine remained open, although California Highway Patrol said they do expect closures over the next several days.

Antelope Valley Snow
Snow is seen along SR-14 in Antelope Valley on Feb. 23, 2023. (Caltrans)

In the Angeles National Forest, The 2 Freeway was closed from 3.3 miles east of Newcomb’s Ranch to Vincent Gulch Road, Caltrans said on Twitter.

Vehicles will be required to use chains between Vincent Gulch Road and Wrightwood, the agency added.

Elsewhere, some foothill communities and even the famous Hollywood Sign could see snowflakes mixed in with heavy rain.

Heavy rainfall

On Friday, rainfall rates of up to 1 inch an hour on the frontal band of the storm will bring the potential for flooding and issues near burn scars. Precipitation totals are expected to be between 2 and 4 inches.

Saturday, the last day of precipitation in the forecast, could also bring heavy showers, lightning and even the possibility of small hail, the NWS said. There is also the potential for waterspout activity over the ocean and brief, small tornados near the coast. 

Dangerous marine conditions with seas peaking between 13 and 22 feet are forecast from Tuesday through Friday. The biggest surf will hit west-facing shores with waves between 7 and 14 feet in L.A. and Ventura counties through Thursday.  

“Sunday could be about the only break in the wet conditions as there is yet another storm system on the horizon possibly as soon Monday or Tuesday next week,” the NWS said.