ICE STORM A FEW DAYS AWAY: The coldest air of the season will spread west of the Cascades between late Wednesday & early Thurs. Many cities in our western valleys will be locked in by freezing air through at least Fri. Temps will gradually warm up this weekend. #PDX #ORwx #WAwx
Initially, cold air will spread all the way down the Willamette Valley & out along the northern Oregon & southern Washington Coast. Eventually, a warmer weather system will erode the cold air away, first along coast, then southern valley, & last in metro area. #PDX #ORwx #WAwx
Precipitation will begin to spread inland Thurs. afternoon, w/ steadier precip. Thursday night. Anything that falls in Coast Range, interior valleys and points to the east will either be snow, a wintry mix or freezing rain. Roads will turn nasty overnight Thurs eve/night.
The Fri. A.M. commute will be extremely difficult to navigate, with a glazing of ice across most valley locations. More waves of moisture will come through Friday - Saturday, not depicted on this graphic.
Depending on location & surface temps, additional ice accumulation will be possible. My gut feeling is portions of central / northern Willamette Valley (including metro area) will get hammered by ice accumulation. The Gorge & Cascades will get snow, & eventually frz. rain.
Remember: all we need is a minor glazing of ice on roads to create major problems. About 1/4” will lead to widespread power outages. Things get really ugly with ~ 1/2” of ice accumulation. Branches/trees down, etc. Think February 2021.
Since the metro area will be exposed to the cold Gorge wind longest, expect freezing temps and icy surfaces through at least midday Saturday. Thawing should occur earlier south & west. It’s *possible* central / east metro won’t thaw out until Christmas Day. 
Forecast will become more clear over the next day or two, such as who could get the most ice & when temps will warm up in specific locations.
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