Valgrisenche

Wind slabs require caution. Backcountry touring and other off-piste activities call for restraint.

Wind slabs require caution. Backcountry touring and other off-piste activities call for restraint.

As a consequence of new snow and a strong wind from northerly directions, sometimes easily released wind slabs formed on Friday at intermediate and high altitudes. Adjacent to ridgelines and at a distance from ridgelines the avalanche prone locations are to be found above approximately 2100 m. They are lying on unfavourable layers. The fresh snow of the last few days and in particular the wind slabs to be found in gullies and bowls and behind abrupt changes in the terrain can be released by a single winter sport participant. The fresh wind slabs are to be avoided whenever possible. These are to be assessed with care and prudence. Medium-sized natural dry avalanches are to be expected as the day progresses, especially at the base of rock walls and behind abrupt changes in the terrain, and on very steep slopes, in the event of solar radiation in particular on sunny slopes. In isolated cases avalanches can penetrate down to the ground and reach quite a large size.

25 to 50 cm of snow, and even more in some localities, has fallen since Tuesday above approximately 2200 m. On Friday on very steep slopes several medium-sized and, in isolated cases, large avalanches were observed. The wind was strong to storm force over a wide area. The fresh wind slabs are clearly recognisable to the trained eye. They are mostly deep, in particular above approximately 2200 m. Towards its surface, the snowpack is soft and has a loosely bonded surface. As a consequence of falling temperatures a crust will form on the surface during the night, in particular on sunny slopes below approximately 2300 m. In all aspects snow depths vary greatly above approximately 2400 m, depending on the infuence of the wind. Adjacent to ridgelines and in pass areas and at high altitude a little snow is lying.

The weather conditions will facilitate a strengthening of the snow drift accumulations. Slight increase in avalanche danger as a consequence of warming.