Guest Post by Verity Jones
While the MSM is all hot under the collar about the Killer heat wave in the mid-East US, not a mention about the massive snow accumulation in the Western USA this year. It’s not just a few roads being late to open due to the excessive snow clearance effort (WUWT: here and here), the snowpack is way above average this year. Good news for water supply; bad news for riverside communities.
Just take a look at the extent of this – the Snotel map from 5th June below shows percent of normal snow-water equivalent. The measurements are mostly off the scale, which if you’ll note only goes up to 140% of normal. From the lack of blue and green dots, I’m taking it that the red ones are errors.
- Map from: NRCS Google Earth SNOTEL Data Layer
From mid-May there has been concern in many areas over the amount of snow and the potential for flooding, but instead of melting rapidly the snowpack has persisted, and even continued to accumulate. As of 9th June almost all states listed here (with the exception of Alaska, Arizona and New Mexico, which have much less than normal) are showing vast excesses of snow for the time of year. For example Utah:
And a different format depiction for Wyoming:
Below is yet another way of looking at it – here for the Upper Colorado (link: http://snowpack.water-data.com/uppercolorado/index.php), specifically the feed into Lake Powell. Now this really made me sit up. The levels were ticking along a bit above average until just after mid-April, then they began to rise, and rise, and rise. This says two possible things are happening – either more snow has been falling, and/or temperatures are just not rising enough to melt what is there. Either scenario says ‘cold’.
On 5th June:
“April 15th is the date of maximum snowpack and basinwide snowpack is currently 66.6% of the April 15th average
Snowpack is 277.9% of the June 5th average.”
Of course you just know that when the melt really does get going you just know that all that snow and the ensuing flooding will be blamed on CAGW.
This got me thinking – at what rate does snow melt? I mean we’ve got some truly gargantuan snow drifts in places – how likely is it that significant proportions of them will remain in places that have not retained snow in summer for years?
The last slide in this EPA presentation gives ranges for melt rate with a degree-day factor. The range seems to be 0.07-0.150 inches per day per degree F. These are estimates for a variety of conditions ranging from partially forested/shaded areas to open sun on a prairie. Although some are quite specific, they are still estimates. Now if we take the example of a 22ft drift in Colorado’s Rocky Mountain National Park (Road opens way late due to massive snow) and look up appropriate degree day figures for the region used with this range of melt rate, perhaps we can get an idea of the potential for residual snow pack at the end of the summer.
Using the U. S. degree-day mapping calculator (Coop, L. B. 2010. . Version 4.0. Oregon State University Integrated Plant Protection Center Web Site Publication E.10-04-1: http://uspest.org/cgi-bin/usmapmaker.pl), the following map is for Colorado, calculated between now and the end of September for a 32F base:
Key 
For the higher altitudes we have 1500-2600 degree days before we might expect reasonable additions if not accumulations of snow again, but, still using guestimates for the actual melt rate it seemed sensible to work with a range:
Starting at 264 inches (22 ft) 8th June, the table shows the estimated snow depth remaining on 30th September depending on the assumed melt rate and number of degree days (above 32F). [Update: The table above was produced on the assumption that the melt rates referred to depth of snow. Having covered a lot more background reading on this today I think I should have read the melt rate as “inches SWE/day*F”. Current rates of melting from the NOAA summary table are 0.1-1.6 inches SWE/day. For a 22ft starting snowpack (estimated as 150 inches SWE) my back-of-envelope calculation suggests melt rates would need to be sustained at >1.25 inches SWE/day to remove this depth of snow by the end of September.]
This suggests to me that at higher altitudes there’ll be significant snow ‘left behind’ this year. Those white patches on the distant mountains will be a welcome return for many – cameras at the ready folks!
More than that though, what effect will this have on local/regional temperatures? There would be increased albedo in the mountains where the snow is retained, and potential for cold air drainage as well as depressed river temperatures from prolonged snowmelt over the summer. These effects might be small, and it is, after all, just one unusual year.
Although this is “just weather”, what if we start to have more ‘higher than average’ years now that the PDO has flipped to a cold phase? High pass road opening dates are well documented in Washington State and, having plotted these for the Chinook Pass and North Cascades Highway, I had previously speculated Is the PDO correlated to road openings?
With many analyses suggesting cooler times are on the way, this year may be exceptional in recent experience, but how many “just one year”s would it take for us to notice the effects?
(Updated from post http://diggingintheclay.wordpress.com/2011/06/10/where-snows-dont-melt/)
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http://nwis.waterdata.usgs.gov/nwis/uv?09085100
http://nwis.waterdata.usgs.gov/nwis/uv?09058000
http://nwis.waterdata.usgs.gov/nwis/uv?09059500
Another factor is the angle of the snow relative to the sun and the direction the snow faces. Past the middle of August any slope facing North or NE will not see much snow melt. This will also enhance the radiative cooling and albedo of those areas.
R. Gates,
Thank you for the link. I’ll give it a try. I’ll also watch for your answer to my second question and appreciate the follow up.
Checked the link and found it to be well beyond my compreshension. I’ll ask my son-in-law about it, as he graduated summa cum laude, UCB, in both his majors, math and computers. I’ve found that the very knowledgable are able to explain things in a way most people can understand. Most confusing are those who have only a little knowledge of the subject.
Jimbo says:
June 12, 2011 at 6:32 pm
If Scheider was correct, then all that is required is a few years of sustained volcanoes popping off around the globe to get the next Ice Age started. Sounds too simple. Probably needs the right conditions to get started. Are we there yet?
It takes a village idiot to raise an eyebrow at the Denver Post. http://www.denverpost.com/search/ci_18244011
The super-abundant, heavy snowfalls of this recent winter might calm most people genuinely fretting the global warming menace. Not Joey Bunch, whose Friday headline reads, “Abundant snowpack is “a small blip” after decades of decline. Mr. Bunch goes on:
The warmers have doubled down in recent months, and I don’t see a republican candidate on the horizon who is going to give them a run for their money.
Theo Goodwin says:
June 12, 2011 at 5:19 pm
Gates, you are a troll who has no idea that he is a troll. You are a very good troll. However, my guess is that you do not want that distinction at all.
————-
Define “troll” and “very good troll”.
Is this supposed to be an “agreement club” where everyone comes and agrees with some standard position? I realize I am in the minority here on WUWT, and upset many skeptics with my perspective, but I think I am generally polite and try to stick to the science and even avoid the underlying political messages that many posters here carry on about. As I’ve said repeatedly here…I care about the science and the truths it can reveal to us. When I read a post here that gets the science wrong or the facts wrong, I speak up. If that makes me a troll, even a ” very good” troll, then I’ll gladly accept that title.
This year’s melt would be cataclysmic in scope.
R. Gates is completely right about warm water in the Pacific evaporating and being driven by the jetstream into cold air regions to fall as snow. This is a pattern that happens pretty much every time there’s a La Nina, as the band of cold equatorial water pushes out warm water towards the north Pacific where the jetstream can grab it. Nothing about this is a surprise or unusual at all. In Washington this is referred to as the “Pineapple Express”.
What is unusual is that there was such a mass of cold air as to cool down that warm jetstream not only enough to drive huge snow falls, but to keep that influx of warm air cold enough to greatly reduce snow melt. That’s the real story. Jetstream dynamics can have a big effect on that, but it is unusual for cold air over the continental US to overpower the jetstream so thoroughly.
But please, people, stop hammering R. Gates about this warm Pacific water. That part is absolutely natural Pacific fluctuations.
Ged says:
“…stop hammering R. Gates about this warm Pacific water. That part is absolutely natural Pacific fluctuations.”
But Gates believes it isn’t natural. Well, maybe not completely. 75% of him believes it’s caused by humans.☺
great for the mountain states, but we really need our water back.
Thanks,
The Great State of Texas
Things are starting to look pretty hairy along rivers that drain the Sierra Nevada.
R. Gates,
Any information on my question?
“Your global map shows global temps that fall in the lower range and higher range as compared to a 29 (correction: 21) year base period (1969-1990). I don’t understand why a very short base period ending 21 years ago is used.”
More MSM coverage, this time talking about the benefits to places like Las Vegas, Phoenix, and SoCal:
http://www.msnbc.msn.com/id/43384724/ns/weather/
The Merced River in Yosemite hits its highest flow rate of the year today but it’s still 20% below the record set in 1983.