Valgrisenche

The more recent wind slabs must be evaluated with care and prudence.

The more recent wind slabs must be evaluated with care and prudence.

15 to 30 cm of snow has fallen since Sunday above approximately 2000 m. As a consequence of a strong northwesterly wind, sometimes avalanche prone wind slabs formed above the tree line. In some localities these will increase in size additionally. In particular in gullies and bowls, and behind abrupt changes in the terrain the prevalence and size of these avalanche prone locations will increase, in the regions exposed to a lot of wind, also at a distance from ridgelines. The fresh snow and all the wind slabs can be released by a single winter sport participant. On wind-loaded slopes and from starting zones at higher altitudes small and medium sized avalanches are possible as the day progresses. Dry and moist avalanches can additionally be released in the old snowpack, mostly by large additional loads.

30 to 60 cm of snow has fallen since Friday above approximately 2500 m, in particular along the border with France. The strong wind has transported the new snow significantly. Over a wide area new snow and wind slabs are lying on a hard crust, especially below approximately 2600 m. Outgoing longwave radiation during the night will be good. The snowpack is moist. This applies in all aspects below approximately 2700 m. The old snowpack is unfavourably layered. At high altitude snow depths vary greatly, depending on the infuence of the wind.

The danger will persist.