Thunder, rain and maybe even snowflakes — a repeat of what Snohomish County saw Wednesday night — are headed to the Puget Sound area Thursday and Friday.

An unstable air mass over the Seattle metro area may cause thunderstorms in the afternoon and evening, National Weather Service meteorologist Chris Burke said.

A convergence zone could bring extra rain to the northern Seattle metro area.

Dipping temperatures also could bring a couple of snowflakes to the highest areas of the region, including Seattle, but it likely wouldn’t stick.

After more than a foot of snow dropped at Stevens Pass and Mount Baker Wednesday, another foot is expected to drop on mountain passes by Friday morning.

Winds shouldn’t be as strong as they were Wednesday, though. In the Seattle area, wind should be 10 to 20 mph, Burke said.