One more weather development this morning, that approaching low pressure center is pulling quite a bit of cold air through the Gorge, more than I expected. In fact it’s deepening east of the Cascade Crest. Auspurger Mountain (~3000′), was 38 degrees at 4am but is now down to 21! The cold air is banking up against the east side of the Cascades. Same thing with a dropping temperature across the river at Greenpoint SNOTEL site at about the same elevation. So the cold airmass over there is around 3,000′ thick. With such thick cold air, temps are now at/below freezing at the west end of the Gorge above about 1,000′ with a strong east wind. Vista House wind sensor froze up around 10am…you can see it here. And at my home I have ice starting to form on trees, but not on the road/pavement. Seems like it needs to be about 30 degrees with freezing rain to get ice on pavement during the day. It’s interesting in situations like this where the temp goes from 34 to 33 to 32 etc…; it’s just raining like normal, and then all of a sudden you notice ice is forming on objects while it continues to rain at exactly the same rate.
If you’ve lived in the Columbia River Gorge long, you know that to get the cold air out, the wind needs to switch to west. There is good and bad news on that front:
Bad: There will be no wind switch and thus no warmup until the very early morning hours. The Ice Storm will continue until that time. Anything that falls will fall as freezing rain or possibly sleet (ice pellets); more thick ice building up on all objects. That could easily add another 1/2″ ice accumulation. There are already trees and powerlines down all over the place out there in the Hood River Valley and east to The Dalles, Lyle etc…; it’ll get worse before it gets better.
Good: Sometime between 4am and daybreak a good surge of 45 degree westerly wind will punch through the east end of the Gorge, aided by a much cooler airmass moving in above too (sounds strange, but this helps mix out the cooler air at the lowest elevations). That breaks the inversion currently in place with below freezing air below but mild temps in the mountains. So tomorrow will be MUCH warmer for storm cleanup.
By the way, if you have good ice storm pictures, send them to firstname.lastname@example.org and we may be able to get them on-air to show others.
Chief Meteorologist Mark Nelsen