Avalanche danger: Snowpack conditions lead to high death rate

By Thomas Watson
Enterprise Staff Writer

Avalanches already kill more people on National Forest lands than any other natural hazard, and this winter has been especially brutal. However, there are steps you can take to make sure you are as safe as possible while still enjoying the outdoors during winter.

Because of a weak layer of “sugary snow” at the base of the snowpack, there have been more avalanches than normal, which has resulted in a devastating number of deaths. 

Ten people died in a span of 12 days around the Western United States.

The layer of what’s called “sugary snow” — soft and loose snow — is now buried deep in the snowpack, and officials expect it will likely remain a problem all winter. 

In addition to the weak base layer, another layer of concern exists within the top foot or two of the snowpack, according to a Forest Service press release. 

This winter has been so bad that Forest Service officials are advising people to avoid travel on or below steep snow covered slopes. Avalanche terrain is described as any terrain between 30 and 45 degrees of steepness, and officials want people to avoid those areas.

For those not sure about the level of avalanche danger in their area, the website www.fsavalanche.org is a great tool for education.

In addition to an avalanche advisory map that depicts current avalanche conditions as reported by U.S. Avalanche centers, there are a number of training tools available.

There is a “Get the Training” page under the safety tab that describes the three conditions that must be present to start an avalanche — slope steeper than 35 degrees, signs of unstable snow and a trigger.

Triggers can be people, new snow or even wind; it doesn’t take much to tip the balance. In addition to the three conditions, the avalanche website also goes into great detail about the two main types of avalanches — slab and sulfa.

One of the most difficult steps in determining the risk of future avalanches is checking for signs of unstable snow. The website states that a typical snowpack is actually a series of different layers stacked on top of each other, and that these layers are formed by precipitation, varying temperatures and wind events that occur throughout the winter.

The Gallatin National Forest Avalanche Center also runs a website that can be a great source of information on local avalanche conditions at www.mtavalanche.com. Like the map on the national site, this site has an interactive local avalanche warning map. As of this morning, the webiste lists the avalanche danger as moderate in southwest Montana.

Based in Bozeman, the Gallatin National Forest Avalanche Center covers 10,000 square-kilometers of land, including the Bridger, Gallatin and Madison mountain ranges. The center also has a Twitter feed, @AvalancheGuys, that gives out up-to-the-minute news updates.

At 7 a.m. today, the center tweeted that “the stability is improving and triggering avalanches has become more difficult, but not impossible.”

With 10 deaths in 12 days, avalanches are extremely dangerous, but you can mitigate some of that danger with education. 

The more educated you are on avalanches, the more fun you can have this winter.


Thomas Watson may be reached at twatson@livent.net.