Jim Frankenfield, Avalanche-Center.org director

If you think this headline sounds crazy I have to agree with you. However, numerous articles in the mainstream media over the past 6 weeks or so have made such a claim. Let’s take a closer look at the reality.

The general argument is that the larger number of avalanche fatalities this season is a result of more people, especially newcomers, going into the backcountry. With the emphasis on newcomers the implication is that they lack the training necessary for their endeavors.

First we need to consider whether this season’s figures are really so far out of line with the last 10 years. Second we need to look at the victims and their experience. And finally we need to look at other factors which may offer a more reasonable explanation, such as the nature of the snowpack this season. We can also consider the experience in a couple other countries, including neighboring Canada.

Alternate opinions and theories are welcome, please feel free to comment. All comments are held for moderation but should be approved promptly, within a few minutes to 24 hours in most cases. Guest posts are also welcome, email snow@csac.org to arrange that.

First – How bad is this season?

The previous blog post addressed this question so this is merely an update.

As of April 12 the US has now had 29 fatal accidents and 37 deaths. The number of fatal accidents is above the 10 year average of 19, but the annual totals range from 9 to 29 (as of April 12). So this season is tied with one other at this point. This is certainly not a very good season, but it’s not unprecedented with regard to the number of fatal avalanche accidents.

As the previous blog post noted, there have been an inordinate number of multiple fatality accidents and by the body count measure the season is far above the average of 20.7 as well as the previous high (within 10 years) of 30.

The number of fatal incidents is arguably a better measure of how bad a season is. Each incident represents one group and one decision making process. One poor plan or poor decision, or one bit of bad luck, can potentially result in one fatality or several fatalities.

We can mitigate the multiple fatality risk most of the time by following safety protocols, but that is not always possible. Climbers are often unable to do things like expose one person at a time to the hazard. And most multi-fatality incidents involve climbing, but those usually occur later in May and June. These issues were brought up in the previous post.

As of April 12 it is not really clear that this season is anything more than one which is at the edge of the range of incidents over a ten year period.

Second – Who Were the Victims?

The majority of the people who died in avalanches this year were not beginners. Most had many years of experience, and in many cases it was reported that they had specific experience and knowledge in the area where they were caught. The average age is not young.

These are largely people who are aware of the local avalanche bulletin, should be familiar with its style and biases, and presumably follow it at least periodically through the winter. Four incidents were in the “side country”, generally accessed via ski lifts but not inside the ski area boundary. The rest were all in the backcountry.

There may be a general increase in the number of people in the backcountry, but that does not appear to be a factor. Few of the victims were new to the backcountry, most had been participating in their activity at a similar level for many years. If there is indeed an influx of new people they are not getting killed in avalanches. Perhaps they show up in other statistics which we do not track here.

Backcountry use has been increasing for many years and its impact has been discussed for many years. If it continued to increase this year then this is just part of a long term trend. There have been years when increased use was discussed which had very few avalanche incidents, so other factors seem to dominate.

Third – The Snowpack

The true source of the problem seems to be the snowpack. About 80% (22/28) of the fatal incidents happened in the continental or transitional snowpack regions. The same problem of a basal persistent weak layer in a thin snowpack existed throughout these regions. There were only 4 fatal incidents in the lower 48 maritime region, which can’t be much out of line with the average. There was 1 in New Hampshire, which is not an unusual number. And two incidents in Alaska, one in which 3 climbers perished and one in a professionally operated heli-ski outing.

Apparently the covid problem only existed in part of the country! And not in the west coast states, or Alaska, or New England.

This persistent weakness at or near the bottom of the snowpack is not unusual, especially in a continental climate where it often persists all season long. These regions frequently have early season snow followed by dry cold weather which weakens the thin snowpack. Subsequent storms load this weak layer with slabs. Additional weak layers may form later as well but anything starting on those is very likely to step down to the early season layer. Just over two thirds of the fatal incidents (and also of the fatalities) occurred in February which seems to be when the weak base was critically overloaded.

The problem was well known and widely recognized. Avalanche bulletins throughout those regions discussed the danger. Some, however, may have confused the issue by discussing a plethora of additional problems which should have been far less influential in decision making and planning. And some recommended digging snowpits to look for this layer, which is misleading and not constructive advice.

The only effective mitigation in these conditions is to avoid terrain over 30 degrees, regardless of any other secondary problems. Digging a pit and not finding the problem does not mean you won’t find it the hard way half way down a slope. In one non-fatal but serious incident an experienced group dug a 2 meter (6 ft) snowpit and decided the snowpack was safe only to trigger a large avalanche nearby where the snowpack was 1 meter deep.

It appears that the real culprit then is not covid at all, but rather an especially weak and dangerous snowpack.

Other Considerations

We can compare this season in the US to the figures in Canada and Switzerland, which both have accessible figures on avalanche deaths.

Canada appears to have 10 deaths in 9 incidents this season, as of April 12. This implies one fatality in each incident with one exception having two deaths. Looking at just the past two seasons this seems to be typical and not out of the ordinary at all. Surely the covid situation north of the border was not that much better than in the US making it hard to consider that as a factor.

Switzerland has had 27 deaths in 26 incidents, also showing a lack of multi-fatality incidents. This is 50% above their average. They are attributing this to the snowpack, with a problem similar to that in the US. There was an early season weak layer at the bottom, with heavy snow loading it enough to produce large to very large avalanches. The number of “side country” (off-piste as opposed to backcountry touring) fatalities has been unusually high there.

The Swiss are not attributing anything to the pandemic, although it seems possible that the increased use has been lift served off-piste activity. In the US there have been reports of heavy side country use to the point of creating moguls in some places. If this is true one result would be compaction and the breaking up of slab continuity which could help stabilize slopes. However, this is merely speculation.

One final consideration is that there were reports of a high demand for avalanche courses this year. Perhaps the people new to the backcountry are taking away the right message from their course about avoiding dangerous slopes in general while some more experienced folks feel like they know enough to pick and choose steeper terrain they can manage. However, this is also mere speculation. There was a study last season which looked at late season incidents after the pandemic began. This was by the Colorado Avalanche Information Center (CAIC) and found that more experienced and educated skiers were getting into trouble more than new skiers.

Conclusion

In conclusion there is absolutely no evidence that this year’s fatalities have anything at all to do with covid or the pandemic. The most likely reason is an especially weak snowpack throughout a large part of the country.

The covid story surely serves the media’s goals of sensationalizing anything possible to attract viewers they can show ads to. It’s not clear why these stories quote experts in support of the covid theory, or what their goal or interest in this questionable story is. Any expert has access to the same data mentioned above and presumably has the ability to analyze it properly.

Opposing views or pointers to additional facts or statistics that may have been missed here are certainly welcome. Feel free to leave a comment. There is no need to register or log in but comments need to be manually approved and will not appear immediately. We also welcome complete posts, if you are interested in writing more than just a comment email us at snow@csac.org and we will arrange a guest post for you.