There is still a localized risk of slab avalanches, in particular above 2500 meters on some north faces in the Tarentaise and Vanoise. As we mentioned in our snow and avalanche bulletin there have been at least a couple of avalanche incidents in this area. If you are ski or snowboard touring this week please note that around 30cm of snow fell last Thursday accompanied by southerly winds. In some areas there are soft slabs sitting on weak facetted snow layers.
Although these are not large they can be sufficient to knock you off your feet and possibly cause a serious or fatal fall. Philippe Feautrier has described an avalanche they triggered (link in French) on Saturday on the north Face of the Dome de Pichères in the couloir Nord of the Col du midi de Bellecôte near the ski resort of la Plagne.
They were climbing through a mixture of hard and soft snow and Philippe noted that the surrounding rocks were covered in a mixture of snow and ice, this made him slightly uneasy; however group dynamics led them to continue. Three of the group were climbing a snow ramp using crampons when they triggered a soft slab avalanche sweeping two people down the slope. They hit a number of rocks during their slide, fortunately they were wearing helmets on this steep terrain. Philippe suffered a severe sprain to his leg when his crampon got caught in hard snow during the slide and also had facial injuries and his friend injured his shoulder on a rock. They descended to casualty at Bourg St Maurice under their own steam helped by other members of the group.
Philippe estimates that the slab was just 20x20m and about 15cm deep. Large enough to sweep you off your feet, especially in a steep couloir. He thinks that they didn’t appreciate the conditions sufficiently, cold air at -10C, soft slabby snow on a hard layer and an accumulation of snow in a small, narrow section. There is also the important question of goal oriented and experienced groups and the effect of negative feedback of many successful trips on similar terrains. It is the end of the season for Philippe, we hope he has a speedy recovery and can enjoy the summer.
Although conditions are spring like and the snowpack is generally stable it should be remembered that conditions are much colder at altitude with the persistence of weak layers. The season is not over, as far as avalanches are concerned. Last April Romain Berger was killed skiing a couloir at La Grave by a small avalanche and well known guide André-Pierre Rhem was killed by an avalanche in a couloir in the Mont Blanc range that swept him over cliffs.