From the Vail Daily (Scott N. Miller):
Snowpack in any given year is compared to a 30-year median of measurements. The 2012 snow year was a historic low. The 30-year part of the chart shows the “snow water equivalent” — the amount of water in the snowpack peaking in late April, before runoff hits.
On average, the snowpack at the Vail measurement site is melted off about June 7. In the 2012 snow year, the snowpack peaked before March 20 at a paltry 12.5 inches of water, and was melted off before the end of April.
This year, as of Friday, the measurement site at Vail was already above the 30-year peak of 22.5 inches. More snow would likely drive the snowpack higher, although this week’s forecast calls for clear, warm weather…
Across the Colorado River basin, of which the Vail Valley is a part, snowpack was 31 percent higher than the 30-year average…
What the runoff season will be like is anyone’s guess, of course. We could have a cool, moist spring that slows the runoff to a relative dribble, leaving rivers rising but clear enough to fish, or we could see a string of warm days in April and May that quickly evaporates the snow and muddies the streams…
Given how quickly snow and water can ebb and flow, [Steve Visosky] thinks the valley is probably in good shape for its water supply for the coming summer. But, he said, things could be better.
“I really think we should have more water storage,” he said. “You hate to see all that water just go down the river and not have it when you need it.”
Meanwhile dust on snow is trending upward, according to this report from John Peel writing for The Durango Herald. Here’s an excerpt:
“The notable thing is that we are still on that same pace,” Chris Landry, director of the center, said Friday afternoon just after posting the most recent report on http://www.codos.org. “That is a pace where the frequency of dust events is much higher than it was 10 years ago.
“We’re not retreating back to the 20th century, when the frequency of these events was much lower,” he said.
What it means in terms of how it affects humans is, first of all, very possibly the snowpack will melt sooner than normal.
Weather to come will still have a large effect, but the bottom line is that when dust settles on the snow’s surface it “dramatically advances” the rate at which snow melts. White snow reflects much of the sun’s energy, but darker-colored dust particles absorb that energy, heat up and contribute to the melting of the snow. That means spring runoffs occur sooner, affecting everyone from farmers and ranchers to river runners.
Another, perhaps less-obvious effect, is that dust in the snowpack can cause a destabilizing effect in the snowpack, making spring avalanches more likely in the backcountry. There’s little that skiers can do to combat that – even skiing earlier in the day may not help, Landry said.
And large dust deposits have a more obvious effect.
“Dust is miserable to ski on,” Landry said. “Essentially, you’re skiing on mud.”
Since 2003, the Center for Snow and Avalanche Studies has kept track of dust events in Senator Beck Basin just to the northwest of Red Mountain Pass. This snow season, five such events have been catalogued in the basin…
Studies show that most of the dust comes from the greater Colorado Plateau, an area that includes all the Four Corners states. Dust storms are exacerbated by soil conditions (drought, for example) and soil disturbance, Landry said.
Although 10-plus years of study was not in itself enough to convince Landry of the certainty of a continuing trend toward dustier snowpack, a paper by Janice Brahney of the University of British Columbia did. Brahney’s study “very clearly verified” a 200 percent increase in dust deposited in western Colorado since the mid-1990s.
“Her paper really validated what was sort of glaring, obvious, but not statistically sound trend in our own dust log,” Landry said. “Now, I do say that this frequency and intensity of these dust storms has definitely increased in the last decades and maybe most dramatically in the last eight to 10 years.”
Overall so far this season, the Center for Snow and Avalanche Studies categorizes dust deposits as “moderate to heavy” and snowpack as “average” for the Senator Beck Basin.
Snowpack in the basin that includes the Animas, San Juan, Dolores and San Miguel rivers was 82 percent as of Friday, putting it below average.