Summit County Citizens Voice

Rosehips are an important source of food for wildlife during the long Summit County winter. PHOTO BY BOB BERWYN.

‘Spooky’ backcountry snowpack still prone to triggered releases; mild temps, cloudy skies expected the next few days

By Bob Berwyn

SUMMIT COUNTY — Thin clouds, a few scattered showers and moderate temperatures will mark the next few days leading up to the winter solstice, with no major storms in the medium-term outlook.

Highs climbing into the mid-20s should help settle the backcountry snowpack a bit, according to forecasters with the Colorado Avalanche Information Center. But the most recent storm, combined with strong winds, built thick slabs of snow on many backcountry slopes above treeline, mostly on slopes with north to southeast aspects.

Observers are still reporting obvious signs of instability in the snowpack, including cracking and collapsing snow, and there has been a significant avalanche cycle, with some large and destructive slides. The avalanche center reported a skier-triggered slide near Breckenridge Wednesday, another incident in which nobody was injured.

The cloud cover will help moderate nighttime temperatures, keeping lows in the teens, and winds the next few days will stay in the 10 to 20 MPH range.

See some photos of recent avalanches on Loveland Pass here.

The subnivean zone

Life under the snowpack continues during Summit County’s cold winter months. Even when the surface of the snow looks smooth and unbroken, tiny critters underneath continue to search for food and move around.

If you could see through the snow covering a field, you would see a criss-crossing network of tunnels and trails created by mice and voles. When the snow melts in the spring, those trails are visible as raised lines over upturned earth.

As little as six inches of snow can protect the subnivean environment, keeping the temperatures within a few degrees of freezing, and in some cases, the layer of leaves and grasses that is slowly decomposing helps generate a little extra heat.

Biologists who study these little critters report that they appear to dig new tunnels each time there is a new snowfall, expanding their network while the snow is soft and fresh. Voles dig vertical shafts through the snow and keep them cleared throughout the winter, possible as escape routes or to vent the tunnel system.

The tiny mammals may seem safer under the snow, but nature’s life and death drama continues during the winter months, as martens slip into the vole tunnels to hunt. On the surface, owls, foxes and coyotes trace their prey by listening, then pounce to try and catch a snack.