Climate Change is destroying XC skiing

[pdxgene]

From the Portland Tribune this week..
http://portlandtribune.com/sl/247224-11 ... f-portland

I'd say scrap the snow gear, get a kayak ...

[Koda]

For those interested the author has updated his thread on the turns-all-year forum to include historical snowfall data and analysys back to 1930's specifically for Oregon including Mt Hood as well as various other points along the Oregon Cascades and coast range. You can read the thread here: http://www.turns-all-year.com/skiing_sn ... 3400.0#bot

Although I find the subject interesting and such has piqued my interest I will let the rest of you follow other forum discussions from here on.

here is a teaser from the other thread specifically on Mt Hood:

[Charley]

Well, consider my mind changed. I have my own feelings about things, but it does seem, from an objective analysis, that the last 50 years or so have not seen a decrease in snow levels. There's a lot of variation from year to year, and that may be enough to explain my interpretation of the snowpack trends.

Thanks!

[retired jerry]

No Charley, you're not interpretting those plots correctly

Yeah, the 5 year average bounces around a lot

But the 10 and especially the 30 year averages have a downward trend

2008 and 2009 had a lot of snow which made the 10 and 30 year averages go up a little, but they were 406 and 380. The anomalously high years in 1940s to 1970s were 474, 450, 425, 423,... - a definite downward trend.

[kepPNW]

I'm with Nat, in that those running averages are highly suspect. Especially given the random starting date. Would like to see the original data, and a regression analysis, before saying there's much to support any trend there. (Though, I also agree with Jerry that it certainly appears to be an ongoing diminishment.)

[Koda]

is it possible that climate change has not impacted PNW snowpack?

[Aimless]

About two years ago I saw a map predicting what areas in North America would see an increase or decrease in annual precipitation due to the effects of climates change in this century. The line demarking the transition from lower average precipitation to higher average precipitation ran almost precisely through Eugene, OR. The upshot was that Oregon was predicted to suffer less disruption to precipitation amounts than most places in the USA.

NB: This was not a prediction concerning snowfall patterns, so that a future with less snowfall being replaced by more rainfall would not have been reflected in the results. The same would be true of whether the precipitation falls in larger amounts but less frequently.

[raven]

The snowfall amounts seems to be dropping -- since the 1870s. The decrease is not linear of course. I put some numbers together for a discussion I hope eventually to start on the rise of timberline. Hard to find useful snowfall data, but I found a continuous series for Portland and a parallel series for rainfall.

I tried to provide the data, but tabs were stripped from my formatting. So: between
1871 and 1879, 1 year had more that 40 inches of snow, 3 more than 30",4 more than 20" and 6 more than 10".
The decade of the 1910s had the last year with more than 40" reported.
The decade of the 1940s had the last year with more than 30" reported.
The decade of the 1960s had the last year with more than 20" reported.
The decade of the 1990s was the last with more than 2 years with 10" reported.

Clearly, snowfall has been decreasing massively in Portland; rainfall is mixed, with increased variability. It follows that the average freezing level has been rising when precipitation has been taking place. Also, we may now be having more precipitation in the shoulder seasons and in summer than was the case in the 1940s and earlier.

One impact on skiing has been the rise in the treeline and the decrease in the open areas to tour through. The secondary impact is an increase in the hardened, needle covered snow and tree pit covered areas that have to be negotiated to get to the alpine areas beyond.

Icy snow in January has been frequent as long as I have been in Oregon. When the sun angle becomes higher in February, the surface melt increases and the skiing improves.

Ski backpacking opportunities always are good into mid-June and usually into July, if one picks the locale properly and carries skis for a bit.

I've managed to ski tour in the current year's snow in every month of the year in Oregon -- and not on glaciers -- although it was very early in August and very late in September. (Neither time was I close to Timberline Lodge.) It must have been great in the 1800s when, from the look of the snowfall data, there would have been years, perhaps many years, when the snow did not melt off in the higher country.

[retired jerry]

"is it possible that climate change has not impacted PNW snowpack?"

Like I was saying, it's complicated.

On the one hand, if the ocean is warmer, more evaportaion, more precipitation, so where it's cold enough, there'll be more snow

At a mid elevation, where there's a lot of snow but it's just a couple degrees below freezing, if it gets a couple degrees warmer it'll be above freezing, so the precipitation is rain rather than snow, so there's less snow

I don't think anyone knows well enough how everything works so it's a big science experiment

"May you live in interesting times"

[drm]

So a few things about trying to decide if the snowpack has changed. The main thing is that you need as wide a coverage as possible over at least 20 years. Snow coverage fluctuates a lot and more data helps to deal with that. One location is not going to tell you much. You need to cover a lot of the Cascades.

Researchers at UW have studied this and have determined that snowpack in the Cascades has declined in recent decades. They came up with 15-30% as the amount. You can easily find this study on a web search. Their study was not focused on low altitude, but it's hard to imagine that low altitudes would have a smaller decline than the mountains overall. I don't have the time or expertise to determine why they found these and the physicist on the other board didn't, but I'm guessing is was breadth of coverage.

The second issue is whether global warming is the cause. You don't have to be a skeptic or denier of manmade global warming (which I certainly am not) to acknowledge that other factors affect the weather and snowpack as well, particularly in a mountain range. The UW study talks a lot about the Pacific Decadal Oscillation. The verdict still seems to be out that global warming is causing any current decline. But I think most researchers are quite confident that over the long term, like later this century, global warming will have a big affect and cause much more significant declines. So by the late in this century, cross country skiing at around 3000 feet is likely to be an historic artifact. This is particularly true since one big snowstorm does not make for decent cross country skiing. You need some storms to create a base that covers rocks and logs, and then more to add nice skiable snow on top of that.