Articles

Avalanches involving people don’t happen randomly. 90% of avalanche incidents are triggered by the victim or someone in their party. In order to play safely in avalanche terrain we need to understand what’s happening with the snow.

Every year we teach almost 100 avalanche classes to nearly 5,000 people across a wide swath of the recreating public: grade school and graduate students, skiers, snowmobilers, ice climbers, search and rescue groups, and ski patrols. Though the groups are diverse, the questions are similar. Here’s some answers the most common ones.

By Ian Hoyer, Ethan Green, Doug Chabot, Karl W. Birkeland

ABSTRACT: Knowing the Extended Column Test’s (ECT’s) effectiveness at different slab thicknesses is critically important for practitioners. To better understand the limitations of the ECT, we used the SnowPilot dataset to investigate the utility of ECTs for providing an index of crack initiation and propaga-tion on varying weak layer depths. The database currently contains 5013 ECTs conducted by 386, pri-marily professional, users worldwide between 2007 and 2016. The broad range of observers and snowpacks in the dataset allow us to examine variations in ECT results with changing weak layer depth across seasons and locations.

By Doug Chabot, Mark Kahrl and James Earl

ABSTRACT: SnowPilot (www.snowpilot.org) is open-source, free software that allows users to graph,
record and database snowpit information. New for this year is an online version of SnowPilot.

In 2002 Karl Birkeland was researching a new stability test, the Stuffblock, and needed willing participants to try it and record their data. Since Karl sits in the cubicle next to me, I was an easy recruit. All that season I filled a stuff sack with ten pounds of snow and dropped it from ever increasing heights, dutifully recording the results in my yellow Rite-in-the-Rain book along with other pit information. It was a relatively easy task.

Spring riding can be some of the best of the season. Good snow coverage, warmer weather and more predictable snow stability (at times) can lead to unmatched riding conditions. Riding ability also improves after a full season which allows riders to push the envelope in avalanche terrain. While spring riding can be the best, it can also hold avalanche hazards not encountered during the colder parts of winter.

There were 15 avalanche fatalities in the western United States in January, 2016, the deadliest January in over 20 years. Five of the fatalities were snowmobilers, one was a snowbiker, six were skiers, two were snowboarders and one was a climber. Avalanches are an equal opportunity killer and do not discriminate. To avoid becoming a statistic follow three simple rules of backcountry travel and learn to manage terrain and snowpack carefully.

By: Doug Chabot

Over the last ten years the US has averaged 27 avalanche fatalities a year. This season is on track to easily meet that. This January there were 11 fatalities in the west, one of the highest Januarys on record.  Statistically, February is no better so brace yourself for more tragedy. Here in southwest Montana there have been two avalanche fatalities so far (as of February 1) with an additional 32 close calls reported.

This winter’s snowpack has been described in the avalanche advisories as bad, poor, weak, unstable, dangerous, and tricky. The reason is simple: the early snows in November transformed into sugary grains of angular facets that do not bond to each other and are exceptionally weak. These facets are the foundation of our snowpack. This foundation is weak, crumbly and poorly supports December’s snowfall.

The snowpack is a record of weather events that take place during the winter.  Heavy snows, wind, even long dry spells, help to create unique layers in the snowpack. The order in which these weather events occur determines both the structure and stability of the pack.