Yeah, 1966-67 was definitely a candidate for a winter that could have done it. Essentially zero in the way of strong offshore flow that entire season, so I'd imagine that UHI afflicted places didn't do much anywhere in the region. Especially on slopes near the water like Downtown Seattle. PDX's lowest is 17 days in 1997-98. Still very doable if these crappier runs today have their way.

These intra trough artic waves have a way of suprising this time of year. Can get a quick inch out of super light moisture.

I don’t think the January 10-17, 2017 period was impressive at all from a 500mb perspective (though the earlier month stuff was) but on the surface that was easily the most impressive weeklong stretch locally in Portland in a while.

I wouldn't doubt EPS AI one bit for sure

It’s quite gooey up here with a crazy gooey pinkish grey sunset that didn’t pick up very well on camera. Reminded me of every post nuclear or zombie apocalypse movie… 55 degrees currently.