Though lowland snow has been replaced with heavy rain, it’s snowing hard on the Cascade passes, making for difficult road conditions for travelers.

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A winter weather advisory is in effect for the Cascade and Olympic mountains with 4 to 10 inches of new snow expected to fall Thursday.

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KIRO 7 Eyewitness News meteorologist Morgan Palmer said the snow will make pass travel difficult on Friday as well.

Early Thursday morning, the weather was adding about 20 minutes to normal travel times between Ellensburg and North Bend.

On Snoqualmie Pass, chains required on all vehicles except all-wheel drive.

On Stevens Pass, traction tires are required.    See mountain pass reports

Both passes have compact snow and ice on the roadway.

The state Transportation Department closed both passes briefly early Thursday for avalanche control, after the heavy snow of the past couple of days.

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Meanwhile, the Mount Baker Highway, State Route 542, and the ski area will likely remain closed east of Maple Falls over the weekend after more than 100 trees fell and are continuing to fall after a series of unusually heavy storms, the DOT said.

The road closed Thursday 10 miles west of the ski area. Because it is so windy, it is unsafe for crews to be in the area, DOT officials said.   Crews will resume working to clear the road once rain, wind and snow decrease.