Northern Lepontine Alps

Weakly bonded old snow on very steep shady slopes.

Weakly bonded old snow on very steep shady slopes.

Weak layers in the old snowpack can be released in isolated cases and mostly by large additional loads at transitions from a shallow to a deep snowpack, when entering gullies and bowls for example. The avalanches can be released in deep layers of the snowpack and reach medium size. The avalanche prone locations are rather rare but are difficult to recognise.

The snowpack will be subject to considerable local variations. Towards its surface, the snowpack is soft and its surface consists of loosely bonded snow lying on a strong melt-freeze crust. This applies in particular in shady places that are protected from the wind. Below approximately 2200 m: Towards its surface, the snowpack is largely stable and its surface has a strong crust. Faceted weak layers exist in the snowpack on very steep shady slopes. The older wind slabs are to be found especially in gullies and bowls, and behind abrupt changes in the terrain.