Wind slabs above the tree line. Weakly bonded old snow is to be evaluated with care and prudence.
As a consequence of a sometimes strong wind from westerly directions, sometimes avalanche prone wind slabs will form above the tree line. These are mostly easy to recognise and can be released in isolated cases at their margins. In particular transitions from a shallow to a deep snowpack are unfavourable. Avalanche prone locations are to be found in particular in gullies and bowls, and behind abrupt changes in the terrain and in shady places that are protected from the wind. Avalanches can additionally in very isolated cases be released in the weakly bonded old snow by a single winter sport participant, in particular on very steep shady slopes above approximately 2200 m, as well as on steep sunny slopes in high Alpine regions. In very isolated cases avalanches can also reach large size. Isolated whumpfing sounds can indicate the danger. In particular areas where the snow cover is rather shallow are unfavourable. Very steep, little used shady slopes are to be evaluated with care and prudence. On sunny slopes individual gliding avalanches are possible. Areas with glide cracks are to be avoided.
Snowpack
dp.6: cold, loose snow and wind dp.7: snow-poor zones in snow-rich surrounding
The fresh and older wind slabs are poorly bonded with the old snowpack in particular on steep shady slopes. Faceted weak layers exist in the centre of the snowpack, in particular on shady slopes above the tree line, as well as on sunny slopes in high Alpine regions. In areas where the snow cover is rather shallow the likelihood of avalanches is higher. Snow profiles and stability tests confirm that the stability of the snowpack varies greatly within a small area in these altitude zones. As a consequence of rising temperatures a crust formed on the surface, especially on steep sunny slopes below approximately 2800 m. Snow depths vary greatly above the tree line, depending on the infuence of the wind. On steep sunny slopes less snow than usual is lying. The snowpack is faceted; its surface is loosely bonded and consists of surface hoar, in particular in shady places that are protected from the wind below the tree line.
Tendency
As a consequence of mild temperatures the snow drift accumulations will stabilise during the next few days. On shady slopes the situation is less favourable.
Danger level
treeline
Avalanche Problem
Wind-drifted snow
Treeline
Wind slabs are to be avoided.
The fresh wind slabs are in some cases prone to triggering. They are mostly rather small but can be released easily, in particular in areas where the snow cover is rather shallow. Avalanches can be triggered in the various wind slab layers and reach medium size in some cases. Caution is to be exercised on steep shady slopes, as well as adjacent to ridgelines in all aspects. Below the tree line: Adjacent to ridgelines the avalanche situation is rather unfavourable. Very steep, little used slopes are to be traversed by snow sport participants one at a time. Individual gliding avalanches are possible. Areas with glide cracks are to be avoided.
Snowpack
dp.6: cold, loose snow and wind dp.7: snow-poor zones in snow-rich surrounding
The wind will be moderate to strong for a temporary period. The fresh and older wind slabs are in some cases still prone to triggering. They are poorly bonded with the old snowpack in particular on shady slopes. Faceted weak layers exist in the centre of the snowpack, in particular on shady slopes above the tree line, as well as on sunny slopes at intermediate and high altitudes. As a consequence of mild temperatures a crust formed on the surface during the last few days. This applies in particular on steep sunny slopes, as well as in all aspects at low and intermediate altitudes. Below the tree line, shady places that are protected from the wind: The snowpack is faceted; its surface is loosely bonded and consists of surface hoar.
Tendency
As a consequence of mild temperatures the snow drift accumulations will stabilise during the next few days. On shady slopes the situation is less favourable.
Danger level
2200m
Avalanche Problem
Persistent weak layer
2200m
Wind-drifted snow
2200m
Weakly bonded old snow requires caution. Wind slabs above approximately 2200 m.
Avalanches can in isolated cases be released in the weakly bonded old snow by small loads, in particular on very steep shady slopes above approximately 2200 m, as well as on steep sunny slopes in high Alpine regions. In very isolated cases avalanches can also reach large size. Whumpfing sounds and the formation of shooting cracks when stepping on the snowpack can indicate the danger. In particular areas where the snow cover is rather shallow are unfavourable. Very steep, little used slopes are to be evaluated with care and prudence. The wind slabs of the last few days are in some cases still prone to triggering. They are mostly easy to recognise but can be released in isolated cases at their margins. They are to be avoided in particular in very steep terrain. Avalanche prone locations are to be found in particular in gullies and bowls, and behind abrupt changes in the terrain and in shady places that are protected from the wind. Caution is to be exercised in particular at transitions from a shallow to a deep snowpack.
Snowpack
dp.7: snow-poor zones in snow-rich surrounding dp.6: cold, loose snow and wind
Faceted weak layers exist in the centre of the snowpack, in particular on shady slopes above the tree line, as well as on sunny slopes in high Alpine regions. The fresh wind slabs are poorly bonded with the old snowpack in particular on steep shady slopes. The snowpack will be generally subject to considerable local variations. Above the tree line snow depths vary greatly, depending on the infuence of the wind. The snowpack consists of faceted crystals; its surface is loosely bonded and consists of surface hoar and faceted crystals. This applies in particular on shady slopes above the tree line. On sunny slopes below approximately 2200 m only a little snow is now lying. As a consequence of solar radiation a crust formed on the surface, especially below approximately 2800 m.
Tendency
A generally favourable avalanche situation will prevail. On little-used, rather lightly snow-covered slopes the situation is a little more dangerous.
