Tuesday, February 9, 2021

That would be something!

Here is a graphic of snowfall thruogh Sunday from today's GFS ensemble. This looks like the major snow event for 2020/21 winter!

That's a foot of snow for Portland and Kelso - and Centralia, south Olympia, Hillsboro and St. Helens! The San Juan islands freeze with outflow from the Fraser River but are protected from precipitation by the Olympic Mts; from Rainier south the Cascades get a major dose of whiteout. It would indeed be something to experience if this plays out! Other models are still doing other things with the cold air and the storm-track, so this composite of a single model is not the absolute word on what's coming.

Lowland snow near the Pacific is always a juggling act; a few days ago the temperatures were a few degrees lower, which added several inches to the snow totals. A degree or two here and there in the atmosphere is only critical in the dark of winter, when a warm layer can melt flakes and drop ice or bitter rain upon us. This region will always do best with a storm dropping south along the coast for some snow - but that cold source can't hold much moisture. To get the big numbers we need a storm to track from the SW with its larger content of moisture. That gets tricky because if it hits the coast too far south we don't get the moisture (Mt. Baker vs Mt. Hood in the graphic), and too far north means the warmer air will disrupt the cold air and disappoint the snowghouls (just south of Portland, where the Columbia Gorge outlet cannot quite reach this time).

Whew. so much for all that! Hoping for about a foot on the hill-top, so at least one saucer can play in the driveway. Bummer that our funding for a rope tow hasn't been addressed yet..


THIS JUST IN - Winter Storm watch issued for 1-5" of snow plus possible ice glaze overnight Thurs-Fri. Should be interesting to see if 800 feet of elevation makes a difference!

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