Bitter cold and wind to follow today's snow

West winds that flowed through the Strait of Juan de Fuca collided with south winds over Puget Sound Monday night, creating a convergence zone and snow over Everett before moving south.

Neighborhoods around the region that are at slightly higher elevations — 200 to 500 feet above sea level — woke to some snow, from one inch in Seattle's Queen Anne neighborhood to three inches in Everett, according to the National Weather Service in Seattle.

As the unstable system moved south to Seattle, there was a light dusting of snow in some neighborhoods and a handful of lightning strikes, said meteorologist Danny Mercer.

By this morning, the convergence zone had moved further south to Tacoma, where it dissolved. "There's not much left of the moisture band. It's falling apart into scattered showers," Mercer said.

The real weather excitement, he said, will come Thursday. That morning, an arctic front moving across northern Canada will reach the Washington border and by Friday and Saturday, Mercer expects "temperatures will fall pretty dramatically," with daytime highs in the 30s. "We'll struggle on Saturday to get much above freezing," he said, adding that temperatures may even get down to 20 degrees in the city. Olympia, where the weather is typically colder during winter months, "could get well down into the teens," he said.

Though it'll be bitterly cold — "the coldest we've been in some time" — the weather is expected to be sunny and dry, Mercer said. Though snow accumulation isn't much of a worry, high winds could be, especially along the western slope of the Cascades, he said. There, winds could blow 30 to 40 mph, and at lower elevations, including Seattle, 20 to 30 mph, Mercer said.

"We will see the wind picking up, which will make it feel even colder," he said.

A wind advisory isn't in effect right now but that could change by Friday, Mercer said.

Though the Seattle area is bound to get a whole lot chillier, it's unlikely we'll be busting any cold-weather records. For the month, the coldest day on record is Feb. 1, 1950, when it was 1-degree Fahrenheit in Seattle, Mercer said. There were other days in February 1950 with single-digit or low teen temperatures and the pattern repeated itself in February 1989. Both years, there was "an arctic outbreak" that forced cold air across the region, he said. The coldest days for this week occurred in 1956, when it was 13 degrees on Feb. 15 and 16.

Though "it's hard after the first week of February to get arctic air" it can happen, Mercer said. "But it's really uncommon."

Sara Jean Green: 206-515-5654 or sgreen@seattletimes.com