Valgrisenche

Wind slabs represent the main danger. Backcountry touring and other off-piste activities call for restraint.

Wind slabs represent the main danger. Backcountry touring and other off-piste activities call for restraint.

As a consequence of a moderate to strong wind from northwesterly directions, sometimes avalanche prone wind slabs will form in the course of the day at intermediate and high altitudes. They will be deposited on unfavourable layers in particular on very steep north, east and southeast facing slopes, caution is to be exercised at transitions from a shallow to a deep snowpack. In particular transitions into gullies and bowls where weaknesses exist in the old snowpack are precarious. Single snow sport participants can release avalanches in some places, caution is to be exercised in particular adjacent to ridgelines. The number and size of avalanche prone locations will increase as the day progresses. In some places avalanches can also penetrate deep layers and reach medium size. The avalanche prone locations are rather rare and are difficult to recognise. As a consequence of warming during the day and solar radiation small and medium-sized dry and moist avalanches are to be expected, in particular on very steep sunny slopes, and at the base of rock walls and behind abrupt changes in the terrain.

On Thursday the wind will be strong over a wide area. The fresh wind slabs will be deposited on a weakly bonded old snowpack. In some localities 5 to 15 cm of snow fell on Tuesday above approximately 2000 m. Towards its surface, the snowpack is soft and has a loosely bonded surface, in particular on shady slopes above approximately 2200 m. Towards its surface, the snowpack is moist, in particular below approximately 2100 m. Weak layers exist in the old snowpack. 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. At low altitude less snow than usual is lying. In the south-east of the region, watch out for the numerous rocks hidden by the little recent snow.

As a consequence of warming and solar radiation, the activity of small and medium dry and moist avalanches will gradually increase.