Northern Lepontine Alps

Wind slabs and weakly bonded old snow represent the main danger. Backcountry touring calls for meticulous route selection.

Wind slabs and weakly bonded old snow represent the main danger. Backcountry touring calls for meticulous route selection.

As a consequence of the strong northwesterly wind, fresh snow drift accumulations will form. These can be released by a single winter sport participant in particular on north to east to southeast facing aspects above approximately 2400 m. The wind slabs are to be found in particular adjacent to ridgelines and in gullies and bowls and generally in the high Alpine regions. Caution is to be exercised at transitions from a shallow to a deep snowpack. From starting zones where no previous releases have taken place in particular the avalanches can in isolated cases reach large size. In particular adjacent to ridgelines and in pass areas medium-sized and, in isolated cases, large avalanches are possible. This applies in particular on very steep sunny slopes below approximately 2700 m, as well as on wind-loaded slopes.

The strong wind will transport the fresh and old snow significantly. In particular at elevated altitudes snow depths vary greatly, depending on the infuence of the wind. In some cases the wind slabs have bonded still only poorly with each other and the old snowpack. Individual weak layers exist in the snowpack on wind-loaded slopes.

The avalanche danger will decrease gradually.