Vail Mountain Snotel site falls victim to beetle kill
SNOW SURVEY PROGRAM
The Snow Survey program at the USDA’s Natural Resources Conservation Service provides western states and Alaska with information on future water supplies. Natural Resources Conservation Service field staff collect and analyze data on depth and water equivalent of the snowpack at more than 1,800 mountain sites and estimate annual water availability, spring runoff, and summer streamflows. For more information visit http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/water/snowsurvey/
VAIL — The deadly pine beetle that has ravaged forests across the Rocky Mountains isn’t only affecting trees. This week, snow scientists from the U.S. Department of Agriculture’s Snow Survey Program visited one of their snow telemetry sites on Vail Mountain to look at how the pine beetle has affected the snow recordings on that site.
Snow telemetry, or Snowtel, is an automated system of more than 600 snowpack and water measuring sensors operated by the Natural Resources Conservation Service of the United States Department of Agriculture around the Western U.S. Generally, they’re located in remote high-mountain watersheds.
Diane Johnson, the Public Affairs Manager for our local Eagle River Water & Sanitation District, has been suspecting for years that something isn’t quite right with Snotel site No. 842, located near the Pika run on Vail Mountain.
“I regularly get my board members and employees of Vail Mountain asking whether the SNOTEL data can be trusted,” Johnson wrote in an email to Brian Domonkos, the Colorado Snow Survey Supervisor with the USDA’s Natural Resources Conservation Service. “Obviously we’re in a high profile area and what’s happening with snow drives our economic engine, so I try to stay on top of this stuff when it seems to be getting a bit out of sync when compared to the weather we are actually experiencing.”
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As a result of Johnson’s letter, Domonkos scheduled a visit to Vail Mountain and Snotel site No. 842 for a process called “ground truthing,” where readings are taken to verify the accuracy of the site’s recordings. When he got there, Domonkos immediately pointed out less trees in the area.
“The small group of trees that are behind us are some of the few remnants of a slightly forested, more dense area that used to be here some five-plus years ago,” he said from the site. “But those trees have since been removed and we believe that we’re seeing more windy conditions that have an effect on the snowpack … We believe that we’re seeing scour.”
Scour is where wind blows snow that would have otherwise settled into the Snotel site away from that recording station. After examining the station and taking some readings, Domonkos said his suspicions were confirmed.
“The readings were pretty much in line with what we had suspected when we were there,” he said. “It looks like there is some scour.”
As a result, Domonkos has noted the difference in the USGS records. Since Snotel site No. 842 has been in operation for more than 35 years, Domonkos said the historical info associated with the site is too important to effect any change in the way it is being recorded. While ground truthing missions have resulted in changes to other Snotel sites, and even the elimination of a site, in this case site No. 842 will just be monitored a little more closely going further, with the scour noted in the readings.
“We probably won’t take any real further action,” Domonkos said. “The readings were off a little bit, but not enough to warrant any adjustments at the site.”