Weisseck, Muhr Valley

Slab avalanches in the snowdrifts can fracture down to deeper weak snowpack layers

Slab avalanches in the snowdrifts can fracture down to deeper weak snowpack layers

Avalanche danger above the treeline is considerable, below that altitude danger is low. Snowdrift accumulations are the main problem. Slab avalanches of medium size can in some places b e triggered even by minimum additional loading, i.e. the weight of one person. In some places above 2200m they can fracture down to deeper weak layers in the old snow and thereby grow to large size. Danger zones can be difficult to recognize due to diffuse light conditions. They occur also distant from ridgelines and on slopes in NW/N/SE aspects. On the Main Alpine Ridge, danger. zones occur in all aspects. In some places, the snowdrifts have been blanketed over, making them difficult to recognize.

The fresh fallen snow has been heftily transported. Inside the fresh snow, short-lived weak layers are forming near the surface. At high altitudes the fresh snow is falling atop a generatlly wind-compressed snowpack surface where the bonding is good. IAbove 2000m the fresh snow and drifts have often been deposited atop faceted crystals near crusts, in some places surface hoar has been blanketed on shady, wind-protected slopes above the treeline. Deeper down inside the old snowpack fundament there are soft layers lodged between hard layers at high altitudes. At low and intermediate altitudes the old snowpack beneath the fresh fallen snow is melt-freeze encrusted. The entire snowpack can start to glide over steep rock plates or grassy slopes.

On Saturday morning, mostly light clouds and good visibility with intermittent sunshine. In the afternoon, dense clouds will move in, fog at higher altitudes. Winds will be light to moderate, mostly westerly. At 2000m: from -9 to 6 degrees; at 3000m: -11 degrees. On Saturday night cloud cover will become more dense, after midnight initial showers can set in, snowfall level at 1500m.

On Sunday, fresh snowfall and winds will lead to increasing avalanche danger levels.