Wind slab
- Above treeline
Backcountry touring and other off-piste activities call for caution. Wind slabs and weakly bonded old snow represent the main danger.
Backcountry touring and other off-piste activities call for caution. Wind slabs and weakly bonded old snow represent the main danger.
As a consequence of new snow and a strong to storm force northwesterly wind, avalanche prone wind slabs will form in all aspects. These can be released even by a single winter sport participant above the tree line. Slopes adjacent to ridgelines are especially unfavourable. Individual avalanche prone locations are to be found also in areas close to the tree line. Mostly avalanches are medium-sized. The prevalence of avalanche prone locations and likelihood of triggering will increase with altitude. Additionally avalanches can also be released in deep layers. Such avalanche prone locations are to be found on steep, little used shady slopes above approximately 2200 m and on steep sunny slopes above approximately 2500 m.
On Tuesday the wind will be strong to storm force over a wide area. The fresh and older wind slabs will be deposited on soft layers in all aspects. The more recent wind slabs will be deposited on surface hoar in some places, in particular on the Main Alpine Ridge and to the north. The snowpack will be prone to triggering in some places. Faceted weak layers exist in the old snowpack, especially on shady slopes above approximately 2200 m, as well as on sunny slopes above approximately 2500 m. Whumpfing sounds and the formation of shooting cracks when stepping on the snowpack are a clear indication of a weakly bonded snowpack.
Fresh wind slabs require caution. As a consequence of a strong wind from northerly directions, further wind slabs will form on Wednesday. The snowpack remains in some cases prone to triggering.
Bulletin data: Avalanche Warning Service South Tyrol, avalanche.report (CC BY 4.0)