Friday, June 24, 2011

Olympic Snowpack is 39,100 Percent of Normal!

I took a look at the latest snowpack report today and was stunned!

As reported by the U.S. Department of Agriculture's Natural Resources Conservation Service the Olympic Mt. snowpack (actually the total snow water equivalent--SWE--of the current snowpack) was nearly four hundred times normal. Here is the official map (click to on it to enlarge):

Most of the snowpack measurements in Washington were 200 to 600% of normal, and Oregon and Idaho had similar values--some into the thousands of % of normal. Montana has several basins into the thousands.

Now having snowpacks tens or hundreds of times normal does not mean we had tens or hundreds of times more rain or snow last winter; normally there is very little snowpack left this late in the season and thus having a substantial snowpack can give you very large numbers (where snow is usually melted off completely you could get infinity!). But no matter how you cut it, we have an amazing snowpack for this late in the season.

Why so unusual? We started with a very good spring snowpack after a cool, wet La Nina winter, and one of the coolest springs (now summer) on record is allowing the snowpack to remain. To illustrate, lets look at the temperatures at Stampede Pass at roughly 4000 ft in the Washington Cascades over the past four weeks and compare those temperatures against the normal highs and lows:
Only a a handful of days got above normal and most never even got close to the normal highs. On many days the high temperatures barely reached the average lows!

This kind of substantial late season snowpack provides a serious flooding risk, so it is good that we are not warming up quickly. A major heat wave situation would cause a number of rivers to overflow their banks--particularly overthe eastern slopes of the Cascades. I should note that the northern Rockies have a huge snowpack as well and the melting of that snow is resulting in historic flooding over the Dakotas right now.

We should not forget that the large number of dams on the Columbia not only provide hydroelectric power and water for irrigation, but they serve a flood control role. This week I was talking to a meteorologist at the Bonneville Power Administration and he said that their calculations indicated that without the dams, Portland would have had substantial flooding starting two weeks ago. Before the dams went in, major springtime floods were not unusual on the Columbia. The most dramatic example was the Vanport, Oregon flooding in 1948.

Vanport was a town on the Columbia River near Portland that was flooded and essentially destroyed, killing 15 and leaving 6000 homeless (see pictures bel0w). A huge snowpack had built up in the mountains, and warm temperatures leading up to the Memorial Day weekend initiated a surge of floodwaters moving down the Columbia--with few dams to intercede and stop the waters (check my book for more details on this event)

So we should hope for a slow warm up--and there will be plenty of water for irrigation and hydroelectric generation this summer.

The irony of the current situation is that it not only is good for hydropower but for wind energy as well. As shown in visible satellite imagery, almost every day this spring (like today--see below), the western side has been inundated with clouds and cool air,

while the eastern part of the state is warmer and sunny. Cool air is associated with high pressure, warm air with low pressure--and thus we have a large difference in pressure across the Cascades. Air rushes through the Columbia Gorge and through gaps in the Cascades, right into the major windfarm projects. Thus, this is a very good year for wind power as well.

The problem, as discussed in the press, is that there is not enough transmission capacity for all this clean, renewable power, and as as result the wind farm folks have been forced to feather their turbines, losing large amounts of money in the process. Not good for wind farm owners, probably really good for lawyers.


Cliff Mass Weather Blog said...

SMR and Kiwibru...thanks so much for your corrections...I shouldn't do these blog when I am sleep deprived...let me know if I missed anything else!..cliff

John McBride said...

Cliff, I'm not suggesting that this IS happening, nor that it will, but I am posing a serious question formed entirely from lack of information.

The question is, in many words, I always labored under the belief that ice ages owed to "cold" in the sense of cold springs and summers, and colder autumns and winters.

But is it possible, maybe even just in part, that a small shift in climate, such as we're witnessing right now in our region, but for a decade and longer, could result in the accumulation of snow sufficient to build glaciers, and then ice fields, and advancing ice?

Does it really take an extreme shift in weather to make an ice age, or can an ice age over areas of our hemisphere be the result of "cooler" late springs with late snowfall, some of which at elevation survives owing to greater cloud cover and somewhat cooler temperatures.

Eventually of course, if snow does survive, then more sunlight is reflected which could act to increase additional accumulation, but that's a separate issue from my basic pondering.

And the floods we're witnessing, while historically large relative to modern humanity, are nothing compared to those in the Northwest in geologic time. Could those events have some basis in similar, "late snow accumulations" melted by subsequent "hot(ter)" summer sun?

Being the novice I pose that I'm the student not afraid to ask a question even at the risk of it being a foolish question.

Brian H said...

Absolutely typical for wind power: lots when you don't need it, bupkis when you do.

Pull that plug now.

E said...

You provide such good info on weather - I find myself often recommending your blog.
But would you please consider adding an "about" section? It would add credibility. People have suggest you may not know what you are writing about - "what id he's just a student... etc".

Thanks for writing!
I read every post even though I'm at the edge of your forecasts.

MimiTabby said...

on my way to Darrington friday we saw some amazing clouds. One that really struck me was a lenticular that appeared above a big fluffy one. (thunder cloud?) by the time i got my camera out and took a picture, the upthrusting white clouds had gone through the lenticular. if you would like to see a photo, send me your email address

Cliff Mass Weather Blog said...

Just google my name and email and you will get it my email...cliff

Jonn-E said...

John McBride,
I'll help answer your questions, to which Prof. Mass can add if he sees fit.

1. Your thinking is on the right track. Glaciers move slow enough that we humans often perceive them as static, when in fact there are in constant flux. They are a visual representation of a balance between several different variables in the climate. (as a side note, they all have varying degrees of lag in that representation).
As they are always changing, then yes, you are thinking along the correct lines. Gradual, rather than extreme, change in summer and winter weather can work together to significantly change the size of glaciers. Feedback loops (like the albedo affect you mentioned) can reinforce change in the cooling/advancing direction. There are also counteractive forces though, that tend to limit glaciers from advancing, say, all the way down into the Puget Sound. You need global change rather than local climate change to affect an ice age.

2. The geologic floods you reference are most likely the Glacial Lake Missoula outburst floods . These repeating floods were caused by an ice dam rather than seasonal weather. I encourage you to read about these floods, as they are one of the more sensational stories in earth's history.

Jen said...

Landslides at Mt Rainier this weekend.