NEW : Canada prepares for significant snowfall . Storms could be among area 's nearly 500 worst since Friday . From late Tuesday through early Thursday , 2 feet to 3.5 feet of snow is forecast for the mountains east of Seattle , Guy said . 2 feet to 3.5 feet of snow in the Pacific Northwest forecast . Officials warn of treacherous travel conditions .
NEW : Canada prepares for significant snowfall . Storms could be among area 's nearly 500 worst since Friday . 2 feet to 3.5 feet of snow in the Pacific Northwest forecast . Officials warn of treacherous travel conditions .