This on top of the 1 foot of snow on Thursday night and the 2 feet of snow on Friday. There’s so much snow that chains are required on Interstate 90 (4-wheel drive is not enough).
Actually, chains won’t do much good right now, because westbound I-90 is closed right now due to multiple collisions and spin outs. ( https://www.wsdot.com/traffic/trafficalerts/default.aspx?refnum=307333&action=2&aw=1 )
National Weather Service Spokane WA
Feb 17 2018
…Moderate to heavy snow expected today and Sunday over portions of the Inland Northwest…
A strong and wetter storm system will arrive Saturday morning, delivering snow at times through Sunday. Heavy snow accumulations are possible in the mountains and valleys of northeast and north-central Washington and over much of the Idaho Panhandle. At times, this snow will be accompanied by strong winds over the mountains.
…WINTER STORM WARNING UNTIL 6 PM PST SUNDAY…
* WHAT…Heavy snow expected. Total snow accumulations of 8 to 14 inches, with mountain accumulations of 2 to 4 feet likely near the crest.
* WHERE…Leavenworth, Mazama, Twisp, Winthrop, Stehekin, Conconully, Blewett Pass, and Loup Loup Pass. Most of the valley snow is expected to occur over the upper portions of Lake Chelan and the upper Methow Valley.
* WHEN…Until 6 PM PST Sunday.
* ADDITIONAL DETAILS…Travel will be very difficult to impossible in areas of heavy snow. Winds gusting as high as 30 to 40 over the mountains will also lead to areas of blowing and drifting snow on Saturday afternoon and evening. Local gusts over 50 mph is possible south of Lake Chelan. Another round of wind and blowing and drifting snow is possible on Sunday.
Thanks to Kenneth Lund for this link