An unusually mild winter will be taking a wild turn on Thursday as an arctic air mass collides with an incoming Pacific storm directly over the Portland-Vancouver metro area.
The National Weather Service has issued a winter storm warning for noon Thursday until noon Friday for the greater Vancouver area in Washington and the greater Portland area in Oregon.
The warning predicts heavy mixed precipitation, with rain changing to snow or freezing rain in the afternoon, spreading from east to west across the metro area.
Snow, with possible accumulations of 2 to 6 inches, is expected north of the Columbia River and in eastern portions of the metro area.
Ice accumulations of 0.1 to 0.2 inch is possible south of Portland and in western portions of the metro area.
Additionally, cold east winds gusting to 30 to 40 mph are forecast for Thursday afternoon through Friday, with gusts possibly reaching 55 mph near the Columbia River Gorge.
Temperatures will begin falling Thursday afternoon, reaching the 20s by Thursday night and remaining close to or below freezing until Sunday. Low temperatures and gusty winds will create wind chill values of only 10 to 20 degrees Thursday night.
The storm Thursday night and Friday will be followed by additional snow Friday night into Saturday, with more snow on Sunday before precipitation turns to a mix of rain and snow on Sunday.
