The Northwest Snowpack Trend of the Past Fifty Years: The Truth May Surprise You

[OnlinePoker]

The media is full of stories suggesting that global warming has greatly reduced the mountain snowpack in the Pacific Northwest.

Activist "climate justice" groups like 350Seattle have taken the snowpack loss claims even further, suggesting the current snowpack is "half what it should be"

But the truth, backed by observations, contradicts such apocalyptic descriptions, as I will show you in the blog.

Recently, the Office of the Washington State Climatologist (who is Dr. Nick Bond of UW JISAO) put online a wonderful tool for visualizing snowpack at some major locations in Washington State. Plotting up the actual snowpack trend proves to be highly educational.

I am going to show you the change of snowpack for over the past fifty years.

Why fifty years? Because that is the period when human emissions of greenhouse gases have gone up rapidly and when GLOBAL temperatures have risen more quickly (see plot below). If you are looking for a period to see changes in Northwest snowpack driven by greenhouse gas increases, the last fifty-year period is the time to look for it.

https://cliffmass.blogspot.com/2021/03/the-northwest-snowpack-trend-of-past.html

[KT2000]

1. My cousin once called Cliff Mass

to ask him honestly, why he and the weather stations are wrong about the weather so often. Mr. Mass graciously explained why.

[-misanthroptimist]

2. An old denialist-type trick:

Mass uses data from a few stations in the Pacific Northwest (leaving out the trend lines entirely, btw) to imply a refutation of an article that clearly says "US West Snowpack".

I don't know how many times I've seen denialists pull that BS with temperatures, sea-level rise, sea ice...just about anything. It's a persuasive trick but it's utterly dishonest from someone with Mass' training and resume.

[Pobeka]

3. I went and looked at the site Mass used. There does appear to be cherrypicking going on.

To be fair, he used bar charts directly from the site, https://climate.washington.edu/climate-data/snowdepth/ which doesn't allow for trendlines.

I looked at all the monitoring stations on the site, and for the March 31 date he used, would have to say there isn't an obvious trend in the snowpack depth over even the last 70 or 80 years at the few stations that recorded it back that far.

BUT -- being a resident of the PNW, snowpack on Mar 31 isn't that critical -- we're still getting plenty of rainfall, and the seasonal drought doesn't start until June. That's when we need the snowpack to provide water for the large population in the Puget Sound and lower Columbia basin areas.

So I looked at the last date available to make a comparison which is May 1. I could only "eyeball" it, but most stations show declining snowpack levels through the years on May 1. That's worriesome to me for a growing population which is used to having an abundant water supply. in the 36 years I have lived here, there was only one summer we had water scarcity to cause changes in water use.

[-misanthroptimist]

4. It's very difficult to eyeball a trend...

...unless it's obvious. Noisy data, like most any weather data, makes it particularly difficult. Beyond that, there is the fact that choosing a particular date introduces even more noise, as your post indicates. To really get a handle on what's going on would require the use of annual data at as many reliably measured locations as possible over as long a time as practical and germane. Your May 1 analysis, though, is more useful than the March 15 figures used by Mass.

Here in FL, we have a different water problem, particularly in South FL, with rising sea-levels.

There's a reason Nestle is trying to get hold of as much of the world fresh water supply as possible. Nestle is evil, but they're not stupid.

[Pobeka]

5. 100% agree. n/t