Friday, January 14, 2011

Taking the mystery out of avy advisories

Former center director explains danger levels, conditions

Express Staff Writer

Janet Kellam, former director of the Sawtooth National Forest Avalanche Center, demonstrates how to use the centerís daily advisories. Snow conditions may vary by location, as Kellam points out in the onscreen map. Photo by David N. Seelig

If there was one thing Janet Kellam tried to avoid during her lecture on avalanche advisories at the Idaho Conservation League on Tuesday, it was intimidating anyone.

"I won't use any scientific terms," joked Kellam, former director of the Sawtooth National Forest Avalanche Center.

The center issues daily avalanche advisories meant to inform backcountry recreationists about how conservative their plans should be. However, Kellam said the advisories can be confusing to those who don't know how to read them.

"Sometimes the information can be intimidating," she said, and sometimes those who don't know what they are looking for can misinterpret the warnings.

The most straightforward part of each advisory is what Kellam called a "danger rose" or a "danger compass," a circle divided into 24 sections color-coded to represent the level of danger on different elevations and on slopes facing each of the compass directions.

With a quick glance, skiers or other recreationists can tell exactly what the danger level is on a south-facing, high-elevation slope, for example.

The colors of the sections coordinate with the colors listed on the national avalanche advisory scale, which ranges from extreme to low danger.

Kellam said extreme danger, denoted with red, has only occurred twice in the Wood River Valley in 15 years. High danger, represented with red-orange, is more common.

"With high danger, there are a lot of avalanche problems," Kellam said.

This level is often prompted by a large snowstorm, but doesn't normally last more than a few days.

"The snow wants to be stable, it wants to settle down," Kellam said, and new snow typically bonds with the snowpack sooner rather than later.

According to a brochure issued by the center, more people are killed during the "considerable" danger level than at any other danger rating. This level, shown by an orange section on the danger compass, means human-triggered avalanches are likely.

However, that shouldn't stop dedicated recreationists from proceeding with caution, Kellam said.

"When you see the word 'considerable,' it doesn't mean you can't go out very, very safely," she said. "It just means stay away from the steep stuff."

Avalanches occur on slopes steeper than 30 degrees. That can be hard to gauge without a slope meter, but Kellam recommends thinking of Baldy ski runs as reference points.

For example, College and Flying Squirrel are not steep enough for avalanches, though Warm Springs face and the steepest part of Graduate could slide in the right conditions. Kellam said that though a large storm could set up conditions for potential slides, wind and blowing snow can load slopes and cause significant avalanche danger without any new snowfall.

Conditions can vary by day and even by hour, so Kellam urged recreationists to check the advisory daily. Skiers and snowboarders should alert the center of any natural avalanches they spot while playing on the slopes.

"Don't assume that the avalanche center knows about it, because often they don't," she said. "[Recreationist observations] are an immense help."

Conditions can be reported via phone at 622-0099, or online at

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