This in from Seattle Department of Transportation:
Ice and snow continue to make roads slick. Residents are encouraged to make their way home before dark if possible. The National Weather Service issued a winter weather advisory calling for an ongoing mix of more sleet, freezing rain and snow until 4 a.m. Winter weather may impact the morning commute.
The Seattle Department of Transportation (SDOT) had 33 snow response vehicles out this afternoon. The full fleet will continue to plow and treat major arterial roads with salt brine and granular salt overnight. In addition, the City contracted three grading trucks – one of the most effective tools for scraping ice from roadways. The city has 24,000 gallons of salt brine and 1,400 tons of salt in its stockpiles.