Middle Lys Valley

New snow at intermediate and high altitudes.

New snow at intermediate and high altitudes.

10 to 15 cm of snow, and even more in some localities, will fall until Sunday above approximately 2300 m. In the late morning as a consequence of the snowfall there will be an increase in the avalanche danger within the current danger level. In particular on extremely steep slopes mostly small dry and moist avalanches are possible at high altitudes and in high Alpine regions. As the day progresses as a consequence of the ceasing of precipitation there will be only a slight increase in the danger of moist and wet avalanches, especially in the regions exposed to heavier precipitation below approximately 2700 m. As a consequence of new snow and wind from southeasterly directions, mostly small wind slabs will form in particular in places that are protected from the wind. As a consequence of a moderate to strong wind from northwesterly directions, small wind slabs formed by Friday in particular at high altitudes and in high Alpine regions. The fresh and older wind slabs can be released by a single winter sport participant in isolated cases, in particular on extremely steep slopes.

Outgoing longwave radiation during the night will be reduced. The surface of the snowpack will freeze to form a strong crust only at high altitudes and will soften later than the day before. 2 to 10 cm of snow fell on Wednesday above approximately 2500 m. In the last two days the wind was moderate to strong. The weather conditions facilitated a gradual strengthening of the snowpack on Friday. Towards its surface, the snowpack is moist and its surface has a crust that is strong in many cases. Below approximately 2100 m a little snow is lying.

The backcountry touring conditions in the morning, after a clear night, are favourable. As the day progresses as a consequence of warming during the day and solar radiation there will be an increase in the danger of moist and wet avalanches for a short time.