As a storm and cold air plunge southward, heavy snow and travel delays will expand over the interior Northwest and northern Rockies Friday into this weekend. The cold will head eastward next week.
The setup will produce low snow levels and locally heavy accumulations of the white stuff in the Northwest.
Expect slow travel over the passes along I-90 in Washington, Idaho and western Montana to begin in earnest on Friday. High winds may add to the travel problems through the mountains and over the High Plains with blowing and drifting snow.
Six to 12 inches of snow is forecast over Snoqualmie and Lookout passes. Motorists who must head cross country Friday into Saturday are encouraged to take a more southern route, such as I-84.
A moderate snowfall is forecast in Spokane, Wash., and Missoula, Mont.
Rain will fall along the Washington coast, including in Seattle, Tacoma and Bellingham as well as in Portland, Ore.
The new push of arctic air aimed at the United States will first hit a little farther west this time when compared to the last cold blast. However, the arctic air will still have eyes for the Plains, Midwest, Northeast and South next week.
The air mass has the potential to be as cold or even colder than the arctic air affecting the Central and Eastern states this week.
For starters, the air could bring the first day of the season with high temperatures in the single digits over the High Plains of Montana and highs in the teens in a portion of the the Dakotas to Minnesota.
The snow may not stop over the northern Rockies and High Plains. There is a chance of a swath of snow developing farther east from the central Plains to the Upper Midwest early next week, just as the new push of cold air arrives.