Middle Lys Valley

Weak layers in the old snowpack represent the main danger.

Weak layers in the old snowpack represent the main danger.

The new snow of last week has bonded quite well with the old snowpack. Especially places where weaknesses exist in the old snowpack are unfavourable. This applies in particular on very steep shady slopes at the base of rock walls and behind abrupt changes in the terrain. Here the avalanches can be triggered in the weakly bonded old snow and reach medium size. Isolated whumpfing sounds indicate the danger. Older wind slabs are covered with new snow and therefore difficult to recognise. They can be released, especially by large additional loads,, especially at their margins. This applies in particular on extremely steep slopes, and in steep rocky terrain.

In recent days, 20 to 30 cm of snow has fallen above approximately 2,000 m in the areas bordering Piedmont, and 5 to 20 cm in the rest of the territory. The sometimes moderate wind has transported only a little snow. 5 to 20 cm of snow will fall until Sunday. Mainly along the border with Piedmont. Faceted weak layers exist in the old snowpack in particular on shady slopes. At intermediate and high altitudes snow depths vary greatly, depending on the infuence of the wind. Slopes adjacent to ridgelines in all aspects: Towards its surface, the snowpack is hard. Especially slopes in places that are protected from the wind: The snowpack is soft. The formation of surface frost is reported at various exposures and altitudes.

Some snow will fall. The wind will be strong in some localities. These weather conditions will cause a gradual rise in the avalanche danger in the afternoon.