Upper Susa and Chisone Valleys

New snow and wind slabs above the tree line. A dangerous avalanche situation will persist.

New snow and wind slabs above the tree line. A dangerous avalanche situation will persist.

As a consequence of new snow and a moderate to strong southeasterly wind, sometimes deep wind slabs formed. Medium-sized and, in isolated cases, large natural avalanches are possible. Even single winter sport participants can release avalanches in some places, including medium-sized ones. The avalanche prone locations are to be found adjacent to ridgelines and in gullies and bowls, and behind abrupt changes in the terrain. In particular on steep shady slopes the avalanches can be triggered in the old snow. Whumpfing sounds and the formation of shooting cracks when stepping on the snowpack are a clear indication of a weakly bonded snowpack. Remotely triggered avalanches are possible. The current avalanche situation calls for experience in the assessment of avalanche danger.

Over a wide area 50 to 80 cm of snow, and even more in some localities, has fallen since Tuesday above approximately 2000 m. In the last few days easily released wind slabs formed at intermediate and high altitudes. The new snow of last week is bonding only slowly with the old snowpack. Large-grained weak layers exist in the old snowpack on shady slopes. Boxing Day: Artificially triggered avalanches and stability tests have confirmed a dangerous avalanche situation on very steep slopes.

The weather will be sunny. The weather conditions will facilitate a gradual stabilisation of the snowpack.