By Chad Abraham
Aspen Daily News
The combination of a big snow year and quickly warming temperatures could trigger avalanches of unprecedented size, the Colorado Avalanche Information Center announced in an unusual press release Friday.
And slides could be triggered in areas not known for slides or in pathways that haven't "run in decades," says the release, written by center director Ethan Greene. Slides also may "run farther than they have in recent memory."
The center has never before sent out such a press release, he said. But Greene described the so-called set-up conditions for avalanches as "unprecedented," and said some places have "as much snow as we've ever recorded." And warmer-than-expected temperatures are predicted this weekend.
Snowpack-measuring gauges in the upper Roaring Fork and Fryingpan valleys all continue to show average depths well beyond 100 percent of an average year and in two sites along the Fryingpan exceed 200 percent of average, according to the Natural Resources Conservation Service website.
"In many areas snow was still accumulating through the end of April," the CAIC release says.
Green said the slide near Taylor Pass outside of Aspen on April 28, which caught local skier Nick DeVore, also was a factor in sending out the warning. DeVore survived and was treated for a broken femur and blood loss.
As an example of the size of slides that are possible, the release details an "unusually large and destructive [natural] avalanche" that struck the Peru Creek drainage near the town of Montezuma, in Summit County, April 30.
"This avalanche destroyed large, 100-plus year-old trees as well as a high-voltage tower that was installed in the 1970s," according to the release. "This was an isolated event, but an indication of what is possible this spring." Greene said the avalanche fracture line was 800 feet wide and 10 feet deep.
Similar slides "may not happen," he said. "But we see a lot of indications that it could happen over the next month."
Sending out such warnings—which are directed in particular toward local governments and private companies with workers in the field—"is difficult for us," Greene said. "We don't want people running down the hills for Kansas, but our job is to safeguard people."
The goal is to get the word out that the potential for something unusual exists and to ensure people are not caught off-guard.
"This warning also applies after an avalanche, as it is important people do not enter debris zones until the area has been evaluated for further avalanche activity potential," the release says.
A rapid warm-up also could trigger substantial mudslides and debris flows, according to the Colorado Geological Survey. Similar conditions in 1984 led to more than 40 mudslides and debris flows in the Eagle River Valley.
The avalanche information center also reminds rescue and demolition workers and others to carry proper avalanche rescue equipment and use safe travel protocols. Center employees can advise on spring and slide safety; backcountry advisories are available at www.colorado.gov/avalanche through May 30; and in an emergency, the center can be reached at 303-204-6027.