Deepening snow elevates avalanche concerns
Ryan Summerlin March 10, 2013
Patrollers at local ski areas reported seeing at least 10 avalanches along the Ten Mile Range over the last several days as recent storms continued to load the backcountry with fresh snow.
The Colorado Avalanche Information Center has tracked three-dozen significant slides across the state in the last seven days alone.
But the release of layers of softer, new fallen snow isn’t what avalanche experts are worried about. It’s the weak base layer buried deep in the snowpack, which has the ability to release without warning, that has them concerned.
A variable snowpack can give little indication of instability in one area where the older snow is thicker, and then fail under the same pressure in another place where the bottom layer thins out.
“It can crack from above you and bring down that whole slab,” CAIC forecaster John Snook said. “Those are the ones that are really scaring us.”
The new snow has also increased the likelihood of natural – as opposed to human-triggered – avalanches, like the one that apparently released in-bounds on Tucker Mountain at Copper Mountain Saturday afternoon.
“Patrol responded immediately to the area and after a thorough search determined no skier or rider involvement,” Copper spokeswoman Austyn Williams stated in an email.
The avalanche danger rating in the Summit County and Vail zone has been bumped to considerable on all aspects after 8-10 inches of snow accumulated across the region this weekend.
Experts are advising all but the most experienced travelers to avoid the backcountry given current conditions.
“(The risk) has elevated to the point where it’s considerable on all aspects and elevations,” Snook said. “We’re just asking people to be really careful out there.”
The weather is expected to dry out after a 20 percent chance of snow today and Tuesday, possibly warming into the mid-40s or low 50s by the second half of the week, according to National Weather Service forecasts.
But the warmer weather is not expected to mitigate the current avalanche danger. Experts say the weak base layer responsible for the riskier conditions will remain intact until the snow melts in the spring.
Up-to-date weather and avalanche forecasts are available online at Weather.gov and avalanche.state.co.us.