Over a foot of snow could fall in some mountain passes before Saturday.
KING 5 Meteorologist Lisa Van Cise says snow levels will be 2,000 to 2,500 feet, meaning even the lower passes like Snoqualmie will see snowfall.
The passes will receive anywhere from 4 inches to more than a foot of snow by late Friday night.
By seven p.m., Washington State Patrol had responded to several accidents and spin-outs along the pass.
"Oh yeah, we passed two cars in the trench," said driver Mike Wills. "And I said I'm not going to be one of those people."
That's why he stopped and put chains on his vehicle, just in case.
Troopers said chains were required on all vehicles over 10,000 pounds, and oversize vehicles were prohibited.
There was enough snow that Stevens opened for the season Saturday.
The Stevens ski area rarely opens before Thanksgiving. The average opening is December 1.
Some localized showers are possible on Saturday.
Stevens and Snoqualmie could get additional snow on Sunday, depending on where a convergence zone forms.