SEATTLE (AP) — The National Weather Service in Seattle has issued a winter storm warning through Sunday afternoon for the Cascade mountains in Washington and Oregon and said travel will continue to be difficult to impossible around passes.

The agency said Friday that heavy snow is expected to continue at all mountain passes with up to 4 feet of snow in the Cascades and up to two feet in the Olympic mountains. U.S. Highway 12 at White Pass was closed in both directions Friday for hours after a vehicle collision. On Friday night, chains were required on that highway, on Interstate 90 at Snoqualmie Pass and on U.S. Highway 2 at Stevens Pass.

The weather service in Portland, Oregon, issued a high surf warning for the coast and a wind advisory through Saturday morning for southwestern Washington, and greater Portland area.

In eastern Washington, the agency's Spokane office issued a winter storm warning for that region into northern Idaho into Saturday. Spokane Police said on Twitter Friday afternoon after about six inches of snow had fallen that police had responded to more than 100 vehicle collisions.

The weather service says colder air will shift into the Northwest region though British Columbia over the weekend and that lower lying areas in western Washington may see some snow into next week.