Weisseck, Muhr Valley

Fresh wind slab forms snow slab on weak old snowpack

Fresh wind slab forms snow slab on weak old snowpack

The avalanche risk increases rapidly with altitude and is considerable above around 2000 metres and low below. A soft snow surface and surface hoar are overlaid by gale-force southerly foehn winds with fresh wind slabs. Medium-sized slab avalanches can easily be triggered by individuals in some places, especially from north to east, but also in a few places in the west and south sectors. If fresh wind slabs are disturbed, there is a high likelihood of avalanches breaking through into deeper layers. The old snowpack is poorly structured across the board; if fractures are provoked, they tend to propagate. Avalanche prone locations in the persistent weak layer are barely recognisable and should be assessed defensively. Caution should be exercised in particular near transitions from a little to a lot of snow and in the blown-in entrance areas to steep gullies. Remote triggering is possible in isolated cases.

The snowpack is highly variable and areas with little snow alternate with considerable snowdrift accumulations. In general, fresh drift snow layers lie on top of older, often hardness drift snow packs, which are in the initial stages of kinetic metamorphism. Breaks usually occur near the crust, which forms the transition to the completely angular old snowpack. Under this crust, the old snowpack consists mainly of deep rime and angular forms, which are interspersed with other crusts in areas with more snow. On the ground, snow from early winter can sometimes be found in the form of a hard melt-freeze crust.

Strong Föhn! Strong southerly winds will blow from the start, especially in the high alpine areas of the Tauern, which may soon reach the valleys and reach its maximum around midday. South wind gusts with hurricane force winds of 100 to 120 km/h are to be expected at high altitudes. Visibility will often be limited on the main Alpine ridge, with a few snowflakes possible in the afternoon. Temperatures at 2000 m around -2 degrees, at 3000 m around -6 degrees.

The wind slab problem is slowly improving, but the persistent weak layer problem remains.