BOULDER, Colo. -
Dust coating the high-mountain snowpack has accelerated melting and put the brakes on late-spring skiing around Colorado.
Twelve winter windstorms -- a record number since researchers began taking measurements in 2003 -- have layered the snow with reddish dust, which increases solar absorption. A record 125 inches of snow that fell in December on Durango Mountain Resort, for example, is virtually all gone, said Keith Roush, owner of Pine Needle Mountaineering in Durango since 1976.
"We haven't skied as much this spring, because the dust stops you dead in your tracks," Roush said. "It slows you down and throws you off balance. It's like hitting sand."
The reduced risk of avalanches in spring makes May and June the "second ski season" once the lifts close. For those willing to hike, the state's high peaks are generally safe for early-morning summit attempts and ski descents before the sun heats up the snow and increases the wet-slab avalanche danger. As long as nighttime temperatures remain low, a smooth, monolithic snowpack awaits at high elevations.
But not this year.
According to Andy Barrett, a hydrologist with Boulder's National Snow and Ice Data Center, the dust storms originate in the desert Southwest and have had an earlier impact on the Western Slope, although dust from all 12 storms showed up statewide.
On ski mountaineering trips this spring, this reporter encountered a greatly reduced snowpack on 14,083-foot Mount Eolus in the San Juans near Silverton, yet a near normal snowpack on 13,907-foot Fletcher Mountain in the Mosquito range near Breckenridge.
Meanwhile, the Front Range has not been impacted quite as severely, because the cloudy weather and late snow have kept the dust layers buried.
A quick glance at the mountains from Boulder confirms that the Indian Peaks have escaped major dust deposits and are holding their snow well.
Bureau of Land Management spokeswoman Erin Curtis said the statewide snowpack peaked in late May.
According to Tom Painter, an assistant professor at University of Utah and director of the Snow Optics Laboratory, there's been a steady increase in dust events over the last six years, since researchers began taking measurements.
His ongoing study, "The Radiative Effects of Desert Dust Deposits in Alpine Snow," involves researchers from the National Snow and Ice Data Center and Silverton's Center for Snow and Avalanche Studies. Legendary Colorado ski mountaineer Chris Landry, who has many pioneering first descents statewide, is director of the Silverton center and compiles data daily from a monitoring station near Red Mountain pass.
"Lake sedimentation show us that dust deposits from the last century are greater than prior to the Anglo expansion of the West," Painter said. "In other words, before the government put restrictions on grazing, agriculture practices, mining, exploration, etc., conditions used to be worse than this current cycle."
That's cold comfort though.
According to the Washington Post, areas managed by the Bureau of Land Management between 2004 and 2008 saw a 19 percent increase of off-road vehicle use, a 24 percent increase in the number of oil and gas wells, and a 7 percent increase in grazing acreage. Disturbances like these -- plus agriculture, dirt road use, and development -- loosen desert soil and make it more susceptible to being carried off.
"These dust storms correlate directly with the amount of disturbance on public lands," Painter said. "Break up the crypobiotic soil (desert crust), and you lose material."
Combined with the ongoing drought in the Southwest, dust storms are the inevitable result.
"This year what seems to have contributed to the big storms is that late the typical late-winter/early-spring rain never hit the Southwest in 2009. It was bone-dry," Painter said. "This inhibited plant growth, which helps retain the soil."
Most climate projections indicate continued drying and warming for the desert Southwest, according to Painter, so dust storms are the likely scenario for the future.
"From a water-management perspective and from a recreational-user perspective, it's a downer," he said. "Things are changing, and we're all going to have to adjust."