By Mark Esper
Snowpack in the San Juan Mountains is far below the 30-year average, leading to concerns about water availability later in the year.
Statewide, snowpack is 73 percent of normal. That ranks as the fourth-driest measurement in the last 30 years, according to USDA Natural Resources Conservation Service.
“We’re really hurting statewide,” said Chris Landry, director of the Center for Snow and Avalanche Studies in Silverton.
But he noted the San Juan Mountains “have little bits of prosperity,” notably Wolf Creek Pass, where the snowpack is slightly above its 30-year average.
“That’s partly a function of the first storm (in early October) that gave them four feet,” Landry said.
“But the upper Animas is quite dry,” Landry said, with the lowest snow/water equivalent in at least nine years. “The snowpack is just extremely weak overall.
“I’m sure there is concern among water managers,” Landry said. “This is a really bad start.”
But Landry held out hope that “one or two major storms can restore the snowpack really quickly.”
He warned, however, that such storms would also lead to a severe avalanche hazard, given the weak underlying snowpack.
Landry said that in the western San Juan Mountains, 2011 ended “dry and dusty, to boot.”
Portions of the San Juan Mountains do have comparatively better snow cover than the rest of the state.
But Landry said the CSAS’s Senator Beck Basin Study Area at Red Mountain Pass presents a “scroungy scene, with bare south-facing slopes extending well above treeline and wind-blasted, thin snow cover elsewhere.”
Early winter dust may have hastened the burnoff of those south-facing slopes, Landry said, as those layers became exposed from wind stripping and melt during the prolonged periods of sunny weather we’ve experienced.
Landry said the New Year’s Eve windstorm also had a significant impact.
“The ferocious winds undoubtedly resulted in lost snow-water equivalent to sublimation as massive plumes of snow were thrown in the air and carried great distances,” Landry said.
Although the strongest single hour of wind at the Putney Study Plot near Red Mountain Pass was from 8 to 9 a.m. that morning — averaging 55 mph and gusting to 94 mph — it wasn't until a little later in the morning that a distinct haze was visible in the air, probably consisting of a combination of ice particles and dust. That haze persisted into the late afternoon and evening. A tour the next day to our Senator Beck Study Plot for a snow profile found clear evidence of a fresh but comparatively minor dust-on-snow event.
Dust on the snowpack tends to hasten melting and snowpack depletion.