Before the snow and wind started on Wednesday night, I noticed that the top 10 to 40 cm of the snowpack, was starting to become a cocktail of cohesionless grains of snow by early/mid-week (made up of faceted/angular grains and some surface hoar created thanks to the cold temps) which gave that nice soft top layer a sort of granular feel to it rather than the light smooth feel of fresh new snow. I mention this because even though this top layer was nice to ski in earlier this past week (on most slopes except South due to a a nasty melt crust) is now a weak unstable layer buried under the new snow or snow transported by wind. A number of accidental accidents have happened in the last few days..without serious consecuence (in my opinion because there has not been an enormous amount of snow accumulations and these accidents have involved relatively small slabs with not very much snow in the depostition areas). But the potential is there - I heard serious wooomphing twice today. More snow is predicted for this week and that will add to what is already on top of this weak layer.
There is also another persistent weak layer of cohesionless snow deep down (approx 60-75cm or more down) in the snowpack that dates from the cold snap of early/mid December. This layer is still an issue above 2500 metres or so because these slopes/altitude didn’t get the rain in late December that ultimately had a stabilizing effect on the snowpack from 2500 metres and lower. Large increases in weight, like groups of skiers together on a steep slope can trigger a very large/deep slab avalanche due to this deep weak layer.
Météo France is warning people to still be careful on steep East to North to West slopes above 2200-2400 that could be susceptible to the weight of a group of skiers - and if there’s more snow (as is predicted as the week goes on!), these slopes could become more and more sensitive and deeper instability is predicted e.g. the weight of even a single skier could very easily trigger a large slab avalanche.
Have Fun and Be Safe!
Off Piste & Avalanche Awareness Talks in Val d'Isère: Week of 1 February:
Monday 15.30 sharp Basic Talk at the Moris in Val d’Isère
Weds 18.00 sharp Basic Talk at the Pacific Bar in Val d’Isère
You need to show up at least15 mins before the talk to take advantage of the deals on food & drink!
Tickets are €7.50 (one person under 18 per adult free) and includes great deals on food and drinks at each place! Pre-booking on line price is: £6 on www.henrysavalanchetalk.com (if you can’t come to a talk see our on-line talks on the web site)
HAT is taking the Talks on-snow this year for people who want to learn
more in Val d’Isère & Tignes!
See www.henrysavalanchetalk.com for more info on these practical short courses