After checking all the evening maps and models one thing sure stuck out. The cold air in the Gorge isn’t going anywhere until Saturday when a westerly wind should push it out. My previous thinking and forecasts were based on this being a somewhat marginal event temperature-wise. The problem is that the thick snow cover through the entire Columbia Basin is going to keep the “freezer going” through the day tomorrow. At the same time we have a somewhat rare situation where overhead freezing levels are pretty low to start with…around 3,000′ tomorrow.
So precipitation will remain as snow in the central/eastern Gorge through tomorrow evening. That’s a lot of precip still to go! Most likely another 8-12″ from Cascade Locks to Hood River and 5-8″ at The Dalles. That’s quite a snow storm when added to the ~8″ that has already fallen.
Then there is another issue I didn’t anticipate related to that colder than expected air. The east wind will back off, but still deliver a thinner layer of cold air into the WESTERN Gorge. Looks like a solid .50 to 1.00″ of rain coming to that area. That’s a LOT of heavy glazing on trees and powerlines. This might be a bit overdone, but you get the idea on the ice accumulation forecast from our RPM model:
Stay safe if you live in the Gorge!
Chief Meteorologist Mark Nelsen