Yikes! We are having (so far) a nice wet winter with lots of snow.
Where we live, there is a major ski resort (Mt. Baker) and a lot of the local economy depends on the skiers coming up for the weekend. Last year was a very dry winter and Baker was closed for a lot of the time. This year it is very good -- Baker opened with the most base snow of any ski resort on this planet. It seems that the winter conditions might be setting up something else further south in Oregon. From Riverdog:
Do they remember?
...the Christmas Flood of 1964? That was the worst weather disaster of it's kind in Oregon history.
It started like this.
Background on the 1964 flood here. That flood destroyed highway bridges all over the state, as logging debris, whole trees and houses washed into the rivers and creeks. The major highway from western Oregon to the east side of the Cascades was closed for almost a month. Skiers were shanghaied in the resorts for weeks, and since power was out almost everywhere, the Air Force and Army had to paradrop survival supplies to them. The Oregon City falls on the Willamette River, normally a picturesque 40 feet high, was reduced to just fast water that anyone could have canoed over (and some daredevils did). Portland was only saved by an army of it's citizens topping the downtown seawall with six feet of plywood while every welder in town worked feverishly to weld a mile long steel structure to support the new wall. It was a grabass fix, and the water came within a few inches of topping it, but it saved downtown.
These floods set up thusly:
First, early snow piles up in both the high mountains (Cascades) and the Coast Range hills. Then, a warm rain event occurs and the rain combines with the water content of all the snow it just melted and the result is flooding.
Here in Oregon, we actually get a rain-on-snow situation fairly often, every two or three years. It's usually not too bad, because the snow to be melted isn't too deep, or the rain not too heavy, etc.
In 1964, there was 5 feet of snow at the 2500-foot level, and 3 feet all the way down to 1500 feet, which takes in most of the Coast Range hills. There was snow almost down to the valley floor. Also, in 1964, the foehn event (warm wind and rain) was severe, with the freezing level rising to over 10,000 feet and the entire state getting bathed in 4-8" of warm rain.
The most serious precursor to this set up is the snow amount. The weather-warning chart for Oregon has looked like this for a week now:
Riverdog points to a map of current snow conditions and says:
All that pink is heavy snow, in both the Coast Range and Cascades. The snow has been piling up at the 4,000 foot level in the feet for days, and there is over 6 feet of snow up there now, and it is snowing down to 1,500 feet.
The stage is certainly set as far as the low snowpack goes. We shall see if a foehn system (or "pineapple express" as they are known as around here) develops. We get 3 such systems through Oregon in an average year, and the climatologists tell us that this will be a wetter than normal winter.
Flooding is nothing new to this part of the country either -- we have incredibly good drainage where we live but last winter, we had a week of 15 degree weather and then a Pineapple Express came through and dumped six inches of warm rain in one day. To our south are the lahar flats of Skagit County -- excellent farm land but you see that most of the older houses are built with the main floor several feet above ground level. Let's hope that our neighbors to the south are able to dodge this one...
