60cm of fresh snow has fallen over the last 36-48 hours in the Isere, Hautes-Alpes and border regions with Italy above 1000 meters altitude, around 30cm elsewhere. The new snow is humid and dense. At the start of the episode there was a strong southerly wind, later from the north and in the border areas from the east. In most areas the fresh has fallen directly on the ground below 1800 meters on north and 2500 meters on south facing slopes.
The exception are the Italian border areas (Haute Maurienne, Briancon, Queyras) which received fresh snow on the 10/11th November. Ski tourers had noted a weak layer of hoar crystals in these sectors, a layer that had been covered with windslab on north facing slopes under the influence of the foehn wind last weekend. Skiers triggered a slab of 150cm on the 25th on the north side of the col du Galibier as well as other slides.
Jean-Pierre Sartre, forecaster with Meteo France “In the Ecrins there’s been a lot of wind at altitude. That moves the snow and overloads accumulations that could then slide. With the amount of snow in the Ecrins the risk of spontaneous snow slides is significant above 2000 meters altitude. There has been a meter of snow in the sector. If you want to put a figure on it, the risk is 4 on a scale of 5. The snow pack is very unstable, especially at the interior of the Ecrins range.” Piste patrollers at les Deux Alpes have also reported a number of positive results during their avalanche control work today. In brief great care should be taken, particuarly on north sector slopes above 2200 meters, this weekend.