Upper Passeier Valley

Weakly bonded old snow requires caution.

Weakly bonded old snow requires caution.

Weak layers in the old snowpack can be released in some places by individual winter sport participants. The avalanche prone locations are to be found in all aspects above the tree line. The avalanche prone locations are barely recognisable, even to the trained eye. Mostly avalanches are medium-sized. At transitions from a shallow to a deep snowpack, when entering gullies and bowls for example the likelihood of avalanches being released is greater. In little used terrain the avalanche prone locations are more prevalent and larger. The somewhat older wind slabs can still be released in some cases on west to north to east facing aspects above the tree line. As a consequence of a freshening northerly wind, mostly small wind slabs will form adjacent to ridgelines. As a consequence of warming during the day and solar radiation individual moist snow slides are possible as the day progresses. Backcountry touring and other off-piste activities call for experience in the assessment of avalanche danger.

Faceted weak layers exist in the snowpack, especially on shady slopes above approximately 2000 m, as well as on sunny slopes above approximately 2500 m. The somewhat older wind slabs are lying on unfavourable layers in particular on wind-protected shady slopes. Especially at low and intermediate altitudes only a small amount of snow is lying for the time of year. Above the tree line snow depths vary greatly, depending on the infuence of the wind. On sunny slopes the snowpack will freeze during the clear night and form a strong crust, especially at low and intermediate altitudes. The surface of the snowpack is frozen, but not to a significant depth and will soften during the day, especially on steep sunny slopes at low and intermediate altitudes.

Weakly bonded old snow represents the main danger. Slight increase in danger of moist snow slides as a consequence of warming during the day and solar radiation.