RENO — A winter storm snarled holiday travel in the Sierra on Christmas Day, as heavy snow and hazardous conditions shut down an 80-mile stretch of Interstate 80 intermittently throughout the day.

The main link between northern Nevada and Northern California was shut down around 3 a.m. Thursday because of heavy snow whipped by gusty winds that created whiteout conditions. Westbound traffic was held at the Nevada line, while eastbound travelers were stopped at Applegate.

A dispatcher with the California Highway Patrol said the highway reopened just after 9 a.m. But the CHP halted traffic again shortly after 10 a.m.

It reopened about an hour later, but authorities warned of slow going and possible delays throughout the day depending on conditions.

About 2 feet of snow fell overnight in the mountains around Lake Tahoe, to the delight of ski resorts gearing up for a busy holiday ski season.

Only two weeks ago, temperatures were balmy and snow was scarce, sending more people to the golf links than ski slopes.

Since then, some areas have received up to 10 feet.

Travel restrictions also were in effect farther east on I-80 over mountain grades, including a 150-mile section from Winnemucca to Elko.

In western Nevada, chains or snow tires were required on most other routes across the region, including in the Reno-Carson City area.

No major accidents were reported.

NHP Sgt. Blair Harkleroad said traffic around the Reno area was light, and he advised people to stay home if possible.

A winter storm warning was in effect for the Lake Tahoe region until 4 p.m. The National Weather Service said some areas in the higher elevations could receive up to 4 feet of snow from the storm that began on Wednesday.

Snow began falling in the valleys of western Nevada just before dawn, and several inches had accumulated by midmorning.

The weather service said snow in the Reno area would continue throughout the day.

Flights into and out of Reno-Tahoe International Airport were generally on time, with the exception of a few delays, the airport reported on its Web site.