11 p.m. update: If you’ve walked outside, you’ve noticed the blistering cold weather and suddenly icy conditions: walkways and roadways that were once packed snow are now hard, slick surfaces. SDOT has 21 trucks working through the night to plow, sand and de-ice “priority routes,” which include Market St., 24th Ave., 15th Ave., 8th Ave. and Leary Way. WSDOT is working overnight as well, focusing on the major freeways and highways. But still, transportation officials and the State Patrol are warning drivers to stay off the roads Friday morning if possible, due to the ice. The Seattle School District has canceled classes for Friday. And here’s Metro Transit:

“On Thursday afternoon, approximately half of Metro’s and Sound Transit’s bus service in King County was temporarily suspended due to weather and road conditions. Bus passengers should assume that will be the situation for Friday morning as well.”

And this may not be the worst of it. Meteorologists have an ominous forecast for Saturday into Sunday. Here’s KOMO’s Scott Sistek.

“Aside from strong winds, we’ll be putting a lot of moisture on top of a very cold air mass. This could bring a period of widespread heavy snow to the entire region Saturday evening and night. We could see 4-8″ again as a general rule across all the lowlands.”

That’s on top of the snow we already have. “It’s going to be a real mess,” said Brad Colman, chief meteorologist for the National Weather Service in Seattle. “It’s a much more dangerous storm because of the wind element.”