Persistent weak layers
- Above treeline
- Size
- 2
Stability: poor · Frequency: many
Wind slabs and weakly bonded old snow represent the main danger.
Stability: poor · Frequency: many
Wind slabs and weakly bonded old snow represent the main danger.
As a consequence of snowfall and the moderate to strong southwesterly wind, the snow drift accumulations will increase in size. The fresh snow and the wind slabs formed during the snowfall are lying on top of a weakly bonded old snowpack on west, north and east facing slopes above the tree line. Especially here avalanches can be triggered in the faceted old snow. This applies in case of a single winter sport participant. In some cases avalanches are medium-sized. Remotely triggered avalanches are possible in isolated cases. The avalanche prone locations are covered with new snow and are barely recognisable. Whumpfing sounds and the formation of shooting cracks when stepping on the snowpack serve as an alarm indicating the danger.
Up to 15 cm of snow, and even more in some localities, will fall. As a consequence of a moderate wind from southwesterly directions, further wind slabs will form. They will be deposited on surface hoar in some places in particular on shady slopes above the tree line. The more recent wind slabs are lying on top of a weakly bonded old snowpack in particular on shady slopes above the tree line. The old snowpack is faceted and weak. This applies especially in shady places that are protected from the wind. Whumpfing sounds and the formation of shooting cracks when stepping on the snowpack are a clear indication of a weakly bonded snowpack.
The current avalanche situation calls for caution and restraint. The new snow and wind slabs remain prone to triggering. Slight increase in avalanche danger as a consequence of new snow and wind.
Bulletin data: Avalanche Warning Service South Tyrol, avalanche.report (CC BY 4.0)