Gnarly scene from the French Alps where group of skiers witnessed a massive wet avalanche release and nearly overtake a skier on a cat track below. It’s hard to see but @00:37 the lucky skier can be seen bottom left on the track. Find analysis by Henry’s Avalanche Talk below:
Rapid warming, rain and wet snow avalanches:
A common misconception about avalanche accidents is that they’re mainly related to rising temperatures. When I ask people about when and where they think most avalanche accidents occur, they nearly always reply ‘In Spring, on South facing slopes’. It’s an understandable theory because these wet snow avalanches can be very spectacular and destructive. However, as far as avalanche accidents involving humans is concerned, this is simply not true.
At HAT we emphasize that the vast majority of avalanche accidents involve cold, dry snow slab avalanches triggered by the victim on North’ish facing slopes in December, January and February. We emphasize this fact to counter the widespread misunderstanding above that avalanche danger is mainly related to rising temperatures.
Certainly a rapid rise in temperature, rain, etc., usually creates serious instability, especially if it’s the first big temperature rise above freezing and/or rain of the season on a previously cold, dry snowpack. And rain on fresh snow will almost always create instant avalanche activity. So we do need to be aware of this rapid warming, rain effect on the snowpack and the resulting wet and humid snow avalanche. However, this scenario does not contribute to many avalanche accidents where skiers are involved; I believe it is because common sense works well in these scenarios – if one can be bothered to use common sense e.g. not going onto closed runs, roads and paths when ‘nothing happens most of the time’ LINK. Although these types of avalanches don’t claim as many lives as dry slab avalanches do, they still need to be treated with serious respect.
In sum, I think the way you have to look at it is that the danger from rapid warming, rain, etc. is the obvious, conspicuous ‘known’ enemy. The more deadly enemy is the covert, quiet trap of the dry slab avalanche, that you may unsuspectingly walk (ski or snowboard) into despite subtle but clear and ‘obvious’ clues indicating danger.
This video by Aaron Cassells shows a near miss when a wet snow avalanche came down across a CLOSED walking track, narrowly missing a person below (we’ve noticed that many accidents involving wet snow avalanches involve people in closed areas – closed due to avalanche danger).
See the corresponding blog post henrysavalanchetalk.com for more!