Avalanche deaths below average in Colorado | AspenTimes.com

Avalanche deaths below average in Colorado

Bob Berwyn
Summit County correspondent
Aspen, CO Colorado

The Colorado Avalanche Information Center ended its forecasts for the season Sunday, but experts warn that some slide dangers persist in the high country throughout the summer.

There have been avalanche fatalities and accidents in Colorado every month of the year. Spring and summer slides are infrequent, but when the heavy, wet snow does slide, it can take skiers or climbers for a dangerous ride over rocks and cliffs.

This past winter, four people died in avalanches in Colorado. The long-term average annual number of fatalities has hovered around six. All the Colorado deaths occurred within a 10-day span in mid- to late-December, when substantial snows began piling atop a weak early season base.

Across the country, 27 people died in snow slides, 16 of them snowmobilers. Avalanche deaths involving snowmobilers have spiked in recent years, as more powerful machines have enabled people to easily reach slid-prone powder stashes.

Search and rescue pros say the snowmobile community is still catching up on the educational side of the equation. Some local experts also say that snowmobilers are not as likely to be carrying beacons, probes and shovels, the gear needed for speedy partner rescue.

The Colorado deaths included two snowmobilers caught in a single slide near Granby, a former well-known Summit County resident who perished in an out-of-bounds slide on the back side of Aspen Mountain, and a backcountry snowboarder in the mountains near Crested Butte.

The season began on an alarming note, with several deaths inside ski area boundaries across the West, at Squaw Valley, Calif., Jackson Hole, Wyo., and Snowbird, Utah. There was also a close call at Vail, where a skier was trapped in a slide in Blue Sky Basin on terrain that had been cleared by the ski patrol.

In a span of less then a month, between Dec. 14 and Jan. 8, 23 people died in avalanches across North America, 13 of them in the U.S., according to Dale Atkins, vice president for the avalanche rescue commission at the International Commission for Alpine Rescue.

December saw the most recorded avalanche deaths for any December since the mining days, Atkins said in a New York Times interview, commenting for a story about the inbounds deaths.

After several out-of-bounds deaths at Whistler, the resort posted guards at backcountry access points to prevent entry into hazardous terrain.

The culprit in the early season slide cycle was a layer of ice near the bottom of the snowpack that was widespread across the West. But as the snowpack above the ice layer deepened, the hazard diminished and the rate of accidents decreased.

In the end, it was a below-average year for slide deaths. There hasn’t been an avalanche death in Summit County for several years, although two people died in nearby Eagle County, in the East Vail backcountry, in the 2007-08 season.

In a season-ending message on the avy center web site, the forecasters explained that most spring and summer avalanches occur when the snowpack loses strength as water percolates between the layers and individual crystals. Recent rains could boost the danger of wet snow slides, especially when warmer weather returns.

Overnight temperatures are key to assessing the avalanche hazard this time of year. Sub-freezing temperatures solidify the snow pack, enabling safe travel early in the morning and good skiing as the surface of the snow softens.

Being able to squeeze water out of a handful of snow is a warning sign, as is sinking into the snow more than ankle-deep.

High daytime temps can also up the danger, melting cornices and snow around rock outcrops ” likely spots for a slide to start.

Check the avalanche center website for more information at http://avalanche.state.co.us.