The California-Oregon region is bracing for the season’s first major storm, an atmospheric river that could dump nearly 10 inches of rain on the greater Redding area by the weekend.

And while the calendar still shows fall, the storm will begin with wintry conditions brought on by low snow levels.

“It’s definitely our first big storm. I would say depending on how you want to define winter, you could call it the first winter storm,” Sara Purdue, a National Weather Service meteorologist, said Monday.

When will the storm hit Oregon-Northern California?

Much of the rain and snow expected to fall in the area will occur Tuesday and Wednesday, according to the National Weather Service.

The northern Sacramento Valley, including Redding, is expected to receive 6 to 8 inches of rain Tuesday through Friday, according to the National Weather Service.

The heavy rain prompted the weather service to issue a flood watch for the northern Sacramento Valley Tuesday evening through Saturday morning.

A winter storm warning is in effect for the mountains and foothills of Shasta County through Wednesday night. The National Weather Service predicts 8 to 18 inches of snow above 4,500 feet and 4 to 8 inches above 10,000 feet.

Snow is not expected to fall as low as the valley floor.

For Siskiyou County and the Mount Shasta-Shasta Valley area, there is a chance of 8 to 12 inches of snow on Tuesday and Wednesday, said Alexis Hermansen, meteorologist with the National Weather Service.

Snow accumulations will be higher in the mountains surrounding the city of Mount Shasta.

“We could see one and a half to over two feet,” Hermansen said.

Winds will also be a concern in the Shasta Valley north of Mount Shasta, with gusts up to 75 miles per hour Tuesday evening through Wednesday morning, the National Weather Service said.

Snow levels will increase to more than 6,000 feet on Thursday and Friday.

Drivers on I-5 should be prepared; bring snow chains

The mountain tours on Tuesday and Wednesday will be particularly challenging due to lower snow levels.

Chris Woodward, spokesman for the California Department of Transportation, said chain checks are expected to occur on the higher portions of Interstate 5 north of Redding.

“The most important thing drivers need to know is to be prepared, to have chains if you need them,” Woodward said.

Caltrans recommends that drivers check their brakes, battery, wipers, defroster, heater, headlights and exhaust system before heading into the mountains.

In addition to packs, Woodward said drivers should have an ice scraper and shovel, flashlight, warm blankets, water, non-perishable food items and a cell phone.

Motorists can check road conditions on Caltrans’ QuickMap site at https://quickmap.dot.ca.gov.

There’s also a chance Caltrans and the California Highway Patrol will screen motorists for chains 10 miles north of Redding on I-5 at the Fawndale exit, Woodward said.

Screening vehicles allows authorities to gauge traffic through the Sacramento River Canyon, which can be treacherous and is often temporarily closed due to large trucks and other vehicles circling I-5 during heavy snowstorms.

“If we have to close the highway, that screening acts like a kink in the hose, slowing interstate traffic and easing traffic,” Woodward said.

Thanksgiving Travel Outlook

This week’s storm is expected to last through the weekend.

Purdue of the National Weather Service in Sacramento said Monday that it is still early to get an accurate forecast for the busy Thanksgiving week.

“Potentially there will be a damp start – I won’t say a wet start – but a damp start early next week,” she said.

AAA Projects Next week, 80 million travelers will travel 50 miles or more from their homes.

The extended holiday forecast, which includes the Tuesday (Nov. 26) before Thanksgiving and the Monday (Dec. 2) after, is expected to surpass pre-pandemic Thanksgiving travel levels and set a record, AAA said.

David Benda covers business, development and everything else related to the USA TODAY Network in Redding. He also writes the weekly column ‘Buzz on the Street’. He is part of a team of dedicated reporters who investigate misconduct, cover breaking news and tell other stories about your community. Reach him on Twitter @DavidBenda_RS or by phone at 1-530-338-8323. To support and sustain this work, please subscribe today.

This article originally appeared on Redding Record Searchlight: California-Oregon braces for snow and rain with first major storm of the season