Middle Lys Valley

As a consequence of the precipitation the prevalence and size of the avalanche prone locations will increase. Backcountry touring and other off-piste activities call for experience in the assessment of avalanche danger and careful route selection.

As a consequence of the precipitation the prevalence and size of the avalanche prone locations will increase. Backcountry touring and other off-piste activities call for experience in the assessment of avalanche danger and careful route selection.

Above approximately 1400 m snow will fall until Sunday. The new snow and wind slabs are lying on the unfavourable surface of an old snowpack. Above approximately 2300 m medium-sized and, in many cases, large natural avalanches are possible. These can be released in deeper layers in particular on steep shady slopes. In the valleys bordering Piedmont: In the typical avalanche paths the avalanches can in isolated cases reach intermediate altitudes and in some places endanger transportation routes that are exposed. The more recent wind slabs can be released even by a single winter sport participant. Weak layers in the upper part of the snowpack can be released. Such avalanche prone locations are quite prevalent and are barely recognisable, even to the trained eye. Sometimes the avalanches in these loacations are quite large. Areas that are largely protected from the wind where surface hoar has been covered with snow are especially precarious. Remotely triggered avalanches are to be expected. Whumpfing sounds and the formation of shooting cracks when stepping on the snowpack serve as an alarm sign.

10 to 15 cm of snow has fallen since Saturday above approximately 1800 m. 25 to 40 cm of snow, and even more in some localities, will fall on Sunday above approximately 1800 m. Towards its surface, the snowpack is unfavourably layered; its surface is loosely bonded and consists of surface hoar and faceted crystals. Sunshine and high temperatures gave rise on Thursday to moistening of the snowpack in particular on sunny slopes below approximately 2900 m. As a consequence of highly fluctuating temperatures a crust formed on the surface during the last few days, this also applies on shady slopes below approximately 2000 m. In particular at intermediate altitudes less snow than usual is lying. On sunny slopes below approximately 2100 m hardly any snow is lying.

As the precipitation eases there will be a gradual decrease in the avalanche danger.