Forecasters expect another 10 to 20 inches of snow to fall Friday in the Cascades on top of the 1 to 2 feet of snow that has fallen in the last two days.

The National Weather Service says drivers are facing winter driving condition in the mountain passes.

The Transportation Department required chains on all vehicles early Friday on Interstate 90 at Snoqualmie Pass, the state's main east-west highway. The DOT later changed that to a traction tire advisory for Snoqualmie Pass, as well as for Stephens and White passes.

The White Pass ski resort opens Friday.

With colder temperatures in Eastern Washington, the Weather Service said some snow would likely accumulate Friday on lower elevations in the eastern third of the state, including Spokane.

Forecasters expect drier conditions Saturday.