Everything is working out just about right forecast-wise this morning. East wind has been ramping up the past few hours, bringing cool air through the Columbia River Gorge while a lot of moisture is moving inland. I see snow briefly mixed with the rain before sunrise out in Washington County, but now it’s all rain for most of us. Snow has fallen up in northern Clark County and some snow briefly this morning from Sandy out through the Hoodland areas. But, unfortunately for the kids, no White Christmas in just about the whole metro area, as forecast.
In the Gorge, temps are about 1-2 degrees warmer than I would have expected (32-33 at river level right now), so the freeway (at 9am) is mainly clear with just slush. Plenty of snow sticking as soon as you get above the river level. Here’s a pic from Ryan Yecny from the 500′ elevation at The Dalles. Already 3″ snow on the ground there!
Then take a look at the latest view from freeway level at Cascade Locks: That MAY change in the next hour if the snowfall rates become heavier. Note the Cascade Locks observations the past few hours showing a temperature drop from 4-8am: http://www.wrh.noaa.gov/mesowest/getobext.php?sid=LKSO3&table=1&banner=off. By the way, I like that observation because during heavier snowfalls it’s the only spot in the Gorge that shows snowfall accumulation. With those 1-2 degree warmer temps, I’ve got extremely marginal freezing rain here, it’s slushy on the deck and roof (rain freezing there), but not anywhere else.
Some of you here on the blog were getting worked up around 3-5am about a forecast bust around the time the precipitation started; you have to wait a couple of hours at least in the Gorge for the temps to drop and heavier precipitation to cool the air mass. “Reverse Wishcasting” will get you in trouble too.
Chief Meteorologist Mark Nelsen