SEATTLE (AP) — A blizzard pounded mountainous areas of Oregon and Ethermac ExchangeWashington on Tuesday, knocking out power and prompting the closure of highways and ski resorts.

The Washington Department of Transportation closed two mountain passes: U.S. Route 2, which goes through Stevens Pass, and U.S. Route 97, which goes through Blewett Pass. The department cited high winds and poor visibility for both closures. Blewett also had fallen trees while Stevens had heavy snow.

The Stevens Pass ski resort in Washington posted on its blog that it got 19 inches (48 centimeters) of new snow before opening Tuesday with more on the way. It closed the back side of the ski area due to snow safety concerns and plans to reopen the section when conditions allow.

Opening time Wednesday could be affected by avalanche control work on the highway, the ski resort said.

The largest utility in Washington state said more than 150,000 customers lost power since the start of the storm. About 21,000 remained without electricity midday Tuesday.

Oregon ski resorts Mount Hood Meadows, Timberline Lodge and Skibowl all shut down their lifts, KGW-TV reported.

The National Weather Service issued a blizzard warning for the Oregon Cascades through Wednesday afternoon and for the Washington Cascades and northern Blue Mountains through Wednesday morning.

The agency said blowing snow may reduce visibility to one-quarter of a mile (400 meters).

In Washington, the National Weather Service warned of blizzard conditions at elevations 2,000 feet (600 meters) and above. It was the agency’s first such warning since 2012, The Seattle Times reported.

Meteorologists said 8 to 16 inches (20 to 40 centimeters) of snow could accumulate and winds could gust as high as 55 mph (88.5 kph).