Category: General
Posted by: admin
karma: 0 [+/-] -
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.

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Category: General
Posted by: admin
karma: 3 [+/-] -
Comments on this post are welcome and can be submitted at the end. Be sure to click on "read more" below the graph for the complete article/post.

Numerous recent articles in the mainstream media paint a bleak picture of a catastrophic avalanche season in terms of fatalities. It is being blamed on the covid pandemic, like so many other things these days. This blog article will take a look at just how bad the current season really is, and why the number of fatalities alone may not be an honest indicator in the absence of a bit of a deeper look. The question of why the season is the way it is will be left, for the most part, for a follow up article.

The number of fatalities as of March 1, in the US, is 33. Given that the average for the previous ten years is 14.8, and that the previous high during those years was 26, this does seem to be extremely tragic.

However, the number of fatal accidents as of March 1 is 25. While this is significantly higher than the ten year average of 13.5 there is a large amount of variation over those ten seasons. The previous March 1 high was also 25. So in terms of the number of incidents the 2020-21 season ranks at the top so far, but it is not above the previous high. A bad season for sure, but not as overboard as it’s being made out to be.

20210306-2021-3-6-fatals.png
Full size graph, pop-up

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Category: General
Posted by: admin
karma: 6 [+/-] -
Jim Frankenfield

Commenting is now working on our Nucleus blogs, after some php repair work. All comments are held for moderation automatically but should be approved promptly. So feel free to share any thoughts or observations.

There have been 6 fatal avalanche incidents so far this season. As I write this reports are coming in of a seventh with possibly 3 deaths but details are still emerging. (Followed by a few more now too.) The purpose here is to see what we can learn from the first six accidents taken together, about things to be conscientious about and things about this season. The post will not critique any particular incident in any detail.

Observations will be broken down into the categories most avalanche courses are based on: Safe Travel, Equipment and Rescue, Snowpack, Terrain, Weather, and decision making. Some of these categories are more instructive than others.

Reports for each incident are on avalanche-center.org for members, with official and media reports. The same information can be found elsewhere searching one.

1- A snowmobiler in Wyoming, Dec 18
2- A backcountry skier in Colorado, Dec 18
3- Two backcountry skiers in Colorado, Dec 19
4- A backcountry skier in Colorado, Dec 26
5- A side country snowboarder in Utah, Jan 8
6- A side country skier in Utah, Jan 30

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Category: General
Posted by: admin
karma: 4 [+/-] -
While December got the season off to a rough start, especially in Colorado, the number of fatal accidents is neither worse nor better than the average over the past 10 year.

The number of fatal incidents is 5, vs. an average of 5.1. Four seasons were worse, four were better and 2 were they same. (The average is skewed just slightly higher by 7 incidents in the 2015-16 season.)

The number of fatalities is 6, which is just slightly higher than the average of 5.4. Most incidents involved one fatality so most years have the same number of incidents as deaths. This season one incident had 2 deaths. The average of the past 10 years is skewed up a bit from 5 based on last season (2019) which included an in-bounds ski area accident with 3 fatalities.

We can't really compare non-fatal accidents. Many are reported but we don't know how many are not. So this is based solely on the number of fatal incidents and fatalities, which are complete data sets.

The numbers typically increase a lot during the following month or so and we can't make any predictions about what will be yet. However, the season has not been more deadly than average so far as of January 15.

Fatalities up to Jan 15 by season

Full size graph, pop-up
Category: General
Posted by: admin
karma: 26 [+/-] -
The 2010-2011 season ended on September 30 and we have a few overview graphs of fatalities for that season now. The total by our count is 24 individuals and 21 incidents. We are omitting an unwitnessed incident in Washington State which appears to have been a cornice fall that may have caused an avalanche below. The cause of the fatal incident does not appear to have been an avalanche. There are cases like this which are subjective, one year a climbing fall on Mt Hood resulted in a wet snow avalanche. Some counts included it, we considered it to be primarily a climbing fall.

The five year average in recent times has been 25-30 fatalities so this was a below average season.

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Category: General
Posted by: admin
karma: 21 [+/-] -
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Category: General
Posted by: admin
karma: 26 [+/-] -
After the previous entry about March ranking pretty high in fatalities how did this season stack up?

Well, first of all there have only been 14 fatal incidents which is well below average. (This does not count a cornice collapse in WA because it's not clear what role the avalanche played, if any, in the fatality. But this would make it 15.) The average over the previous 10 season is 31 or 32. And second, each of these had only one fatality. So in the US we've had fewer fatalities than usual and no multiple fatality incidents at all. A good winter so far!

Of the 14 fatal incidents 4 were March, or 29%. This makes March the month with the greatest number of fatal incidents and fatalities this season. Keep in mind, though, that the season total is bound to increase some which will lower the percentages shown.

20110402-2011-march.gif

So how does this compare to a historical average? For all fatalities in the previous ten years March ranks fourth, after the preceding three months. Although it is very close to February and March and the difference between the three may be statistically insignificant. The percentage of fatalities is 19%. The number of incidents were not counted for this time period for this blog entry.

20110402-cumulative-march.gif

While this is interesting to review we can't draw too many conclusions from it. The sample sizes are clearly quite different (316 fatalities vs 14). The ten year graph does not distinguish between the different seasons, and there can be wide variations. This seasons graph does not reflect the entire season which will almost certainly increase the numbers, making the percentage for March lower. Although it's unlikely to lose it's top rank.

The distribution for the 1950-2009 seasons differs from that for the last ten. The last ten seasons are probably more representative of incidents today. Going back too far incorporates seasons when backcountry recreation was not as large a factor as it is today. Snowboards didn't exist and snowmobiles rarely got into avalanche terrain.

Looking ahead, there is a marked drop in April. This may not be true every season but on the whole there are less fatalities. Of course this may reflect the diminishing number of people in the backcountry as they transition to biking and boating as well as seasonal snowpack factors.
Category: General
Posted by: admin
karma: 16 [+/-] -
As we begin to enter the spring season the snowpack tends to become more stable, or at least more predictable. But it can take a while to get there. And of course every year is different.

Early spring is always a transition period. Spring conditions are developing but winter weak layers are still active.

Combine these transitional snowpack conditions with longer days, and often with good weather, and the result can be more incidents. At least some years. Every year differs, and different locations have snowpacks that develop differently.

The bottom line, though, is to be careful during this period. As the following two graphs from last season show there can be a large number of accidents in the spring months in relation to the rest of the year.

The first chart is for the US. You can see that last year March was tied with January for the most fatalities in a month, leading even February. It was second in the number of accidents that included one or more fatalities. In April the numbers really dropped off. May and June generally see a few mountaineering accidents.

US 2009-10 Accidents by month:
20110317-2009-month.gif

The second chart is for Canada last season and the difference is even more pronounced.

Canadian 2009-10 Accidents by month:
20110317-2009-month-canada.gif

Remember that these graphs are just for the 2009-10 season, and that every year is different. The snowpack transition from a winter to a spring structure happens differently every year. It can be earlier or later, faster or slower.

A few years ago in many parts of western Canada the spring was cool and wet until very late, at which point rain suddenly fell up to high elevations. This rainfall on a wintery snowpack caused widespread wet snow avalanches and very dangerous conditions as late as May.

So remember that avalanche season is rarely over in March, in fact it may just be peaking in March or April some years.