A major winter storm is approaching Utah, and Thanksgiving holiday travelers should plan on poor driving conditions throughout much of the West.

The Salt Lake office of the National Weather Service said a winter storm warning for all Utah mountains and a snow advisory for western valleys will be in effect through Thursday morning.Heavy snow is likely for the mountains, with 2 to 4 inches expected in the valleys from the storm, which is expected to move into the Salt Lake area about 8 p.m. Wednesday.

Blowing, drifting snow will be a problem as strong, gusty winds, expected to exceed 45 mph in some areas, will move ahead of the storm.

The approaching storm and another on Friday and Saturday should leave more than 2 feet of snow in the mountains, including Bryce Canyon and Brian Head in southern Utah, and approximately 3 to 5 inches in the western valleys, said William J. Alder, meteorologist in charge at the Salt Lake International Airport.

Winds of 40 to 50 mph were reported at 1:30 a.m. by the Utah Highway Patrol on Interstate 15 in south Davis County. Several other places reported similar wind velocities, but the wind had died down by midmorning Wednesday. Snowbird had a 70 mph gust about 3 a.m. Wednesday and a 37-degree temperature reading at about 6 a.m. At 5 a.m., 39 mph winds were clocked at the airport.

Behind the front, winds will shift to the northwest with much colder temperatures in store Wednesday night, Thursday and Friday.

Scattered snow showers could form again Friday as cold unstable air continues to stream into the state, Alder said. Meteorologists said travelers with high-profile vehicles should be alert to the strong winds, especially on east-west highways.

Adjacent states of Wyoming, northern Nevada, Idaho, Colorado and Montana will also be affected by the storm. The western storm left as much as 36 inches of snow in the Sierra Nevadas, including 18 inches around Lake Tahoe.

Motorists were urged to check travel conditions before setting out on Thanksgiving journeys or to prepare for midwinter driving.

"Roadways by Wednesday night and Thursday morning will be slick and snowpacked in many areas of the state. Be careful. Slow down. It's better to arrive alive and late than not arrive at all," Alder said.