(KTXL) — Since 3:30 a.m. on Friday, snow levels have dropped well into the foothills as the most recent winter storm builds up in Northern California.

The National Weather Service shared that northern Sacramento Valley is seeing snowfall on the valley floor while the rest of the valley is experiencing snowfall between 1,000 feet and 2,000 feet.

Snowfall in the Sacramento Valley and Sierra Nevada

A high avalanche warning has been issued for the Central Sierra Nevada on Friday through Saturday, according to the Sierra Avalanche Center.

The warning went into effect at 6 a.m. on Friday and expires on at 6:48 a.m. on Saturday. The warning is for areas below, near and above the tree line.

The avalanche center said that large “cohesive slabs” of wind-blown snow and deep slabs of fresh snow is creating the threat throughout the region.

Layers of graupel between the layers of snow can also cause instability between the layers of snow.

Images from Caltrans cameras show snow sticking and pilling up along Interstate 5 in both Redding and Red Bluff.

The NWS reported on Thursday that the first wave of the storm saw more than a foot of snowfall in places over 2,000 feet.

At around 8:30 a.m. on Friday, the UC Berkeley Central Sierra Snow Lab shared that more than 26 inches of snow fell over 24 hours, bringing their three-day total to 45.1 inches.

The snow lab is expecting to receive another seven to 14 inches of snow through the rest of Friday.

At around 9 a.m., the NWS released preliminary snowfall numbers for some communities in the foothills and the Sierra.

Parts of Nevada County around Grass Valley are recording between 5 inches and 12 inches of snowfall on Friday.

In El Dorado County near Camino and Plymouth between 3 inches and 5 inches of snowfall was recorded.

Road Closures and Chain Controls

Interstate 80

The interstate was closed to westbound traffic at the Nevada State line and in Truckee due to a traffic collision, according to Caltrans. About 7 p.m. on Friday, all westbound traffic on the interstate has been released, Caltrans said.

Westbound traffic on the interstate was also shut down near Drum Forebay in Placer County following a multi-vehicle collision, according to Cal Fire. Officials said there’s no estimated time of reopening as vehicles are being monitored by the CHP.

Officials said four people were transported to the hospital.

Prior to the westbound closure, the interstate reopened for chain controls from Applegate to the Nevada state line in both directions for passenger vehicles, according to Caltrans. Big rigs and other larger commercial vehicles are being held at Applegate.

Highway 50

The truck that caught fire is being pushed off the road and traffic is expected to be released in about 30 minutes, according to Caltrans.

State Route 49

Has been closed in both directions in Sierra County from Downieville to Sattley.

State Route 89

In El Dorado County it has been closed from Eagle Lake Campground to Bliss State Park.

State Route 20

Eastbound lanes are closed at Nevada Street in Nevada County due to spinout, according to Caltrans.