SAN FRANCISCO (CBS SF) — A winter storm could wreak havoc on holiday travel and shut down the main artery connecting Northern and Southern California on Christmas Eve.

The National Weather Service issued a warning to holiday travelers on the Tejon Pass through the Grapevine for Thursday and Friday.

READ MORE: Lawsuit Alleges Low-Income Homeowners Were Manipulated Into Getting PACE Green-Energy Loans

Rain, ice, snow and winter conditions on Interstate 5 through the Grapevine could create travel problems.

READ MORE: COVID: Bay Area Expert Says Michigan's Surge From UK Variant Not Likely In California

“The combination of snow and wind will lead to very hazardous conditions for anyone venturing into the mountains,” warned the NWS statement. “Roads will be icy and road closures are a strong possibility.”

“Even just an inch of snow will wreak havoc on the Grapevine,” said NWS meteorologist Dave Bruno.

MORE NEWS: UPDATE: 2 Dead, 7 Injured, 1 Arrest In Suspected DUI Crash In Pittsburg

Snow levels will start around 5000 feet Thursday, lowering to near 2000 feet by Friday morning impacting the Grapevine, Tehachapi Pass and Walker Pass.