Freezing Rain?

January 7, 2010

Looks very unlikely anywhere west of the Cascades except at the west end of the Columbia River Gorge.  Temps are too warm, temp-dewpoint spreads aren’t great enough for significant evaporative cooling, and little/no radiational cooling tonight due to the cloud cover.  The only reason TV stations are talking about it tonight is because two breathless press releases came out from the City of Portland and ODOT.   Then TriMet came out with a release saying that 40 busses are getting chained up this evening!  Ugh!  Okay…that gets the news people riled up (for good reason!), but really annoys the weather people.  That’s how it works sometime though.

It’s cold enough for freezing rain anywhere east of Troutdale/Gresham and cold air is still lingering on the lower eastern slopes of Mt. Hood, so a touch of freezing rain is possible up there too.

Chief Meteorologist Mark Nelsen


Even Windier Today

January 7, 2010

I snapped these pictures from Google Earth this afternoon. It’s much better if you actually go to the application yourself and scoot around in 3D. It’s the area around Crown Point (Vista House is set on it). A bunch of us got together again today up there and I was sitting there holding an anemometer through through a sunroof when it recorded a gust to 90 mph right beside the steps leading up to Vista House. It only took about 2 minutes to get a gust that strong. Later Steve Pierce recorded a gust to 101 mph. From my previous post it should be clear that I didn’t doubt several different anemometer readings, but I had to experience it for myself. After years of living in the area I knew the wind is always significantly stronger out on that point, but I didn’t realize how much. The effect is quite localized and you can see why when you are up there or from these pictures. There is a long stretch of the Gorge angling up to the northeast all the way to Cascade Locks in the picture to the right. The east wind (actually northeast in this part of the Gorge) runs right down the straight stretch. Then in this area the Gorge turns straight westward. So the wind runs right into the rocks at Crown Point. This area has also been called Thor’s Heights in the past. The wind does actually come from the northeast for a couple miles beyond up on the flat in the Corbett area. You couldn’t get a more perfect spot to accelerate wind up and over an exposed cliff. Add a basically round concrete/stone building, wrap the wind around that and good meteorological times follow! This WAS the “freeway” before I-84 was built in the mid 1950s. All traffic heading to The Dalles had to go around that point. I’ve seen pictures of trucks tipped over there.

At the same time the wind is raging out there, you can look up on the hill and see the trees not moving much. You don’t have to get more than a few city blocks back to find more “typical” Gorge gusts of 50-65 mph on a day like today. You may notice there are some homes just behind, one shows up well-exposed on the 2nd picture. That’s a great view, but a rough 4 months of the year in the winter! There was a restaurant up there in the 20s-40s called the Crown Pt. Chalet. Weather observations were taken during I think a 5 year period in the early 1930s as well. I met a woman that was a weather observer…rough duty don’t you think?

So two thoughts to leave you with.

1. If you want to experience strong wind, this is the place to go when the east wind is blowing in the winter.

2. We now know that East wind gusts of 80-100+ mph are a regular visitor to Crown Pt. from November to February, and maybe 1 or 2 other exposed (hikeable only) spots at the west end of the Gorge. Otherwise it’s rare to see east wind gusts above 70-80 mph.

Oh, and probably some freezing rain in that spot coming up tonight…IF the moisture makes it. More on that later.

Chief Meteorologist Mark Nelsen