Weisseck, Muhr Valley

Skiable terrain is prone to triggering! Wind slab lies on weak old snowpack

Skiable terrain is prone to triggering! Wind slab lies on weak old snowpack

The avalanche risk is moderate above around 1900 metres and low below. Slab avalanches can be triggered in some places by low additional loads and can reach medium size. Both fresh and older drift snow packs as well as the weakly built-up old snowpack can be disturbed, whereby fractures can tear through. Avalanche prone locations increase rapidly from the tree line upwards. They are concentrated from west to north to east, in some places in the southern sector in the high Alps, and generally next to blown-off areas. Drift snow areas should be consistently avoided. Whumpfing collapsing sounds can indicate danger. Terrain traps are less full due to a lack of snow and are therefore more effective.

The snow surface is very different locally. In windless, shady areas, there is surface hoar on the snowpack, but outgoing longwave radiation is reduced. There are areas with little snow next to considerable snowdrift accumulations. A melt-freeze crust usually forms overnight, which softens up to high altitudes on the sunny slopes. In addition, the wind slab begins to build up and is slightly moistened on the surface with sunlight, but is often also hard as a board. At the transition to the old snowpack, there are faceted crystals that serve as a reactive weak layer. Fractures in the persistent weak layer usually occur here. Deeper in the old snowpack there is a sequence of faceted crystals, crusts and a lot of deep rime. Ridges and ridges are often completely blown off.

The night will be clear for the time being, with widespread clouds moving through from midnight, which will frequently affect the sunshine on Friday. Mountains will remain partly clear. The southerly wind will pick up during the day and blow briskly in the open high areas of the Tauern, with wind speeds of around 60 km/h, otherwise moderate to strong. At 2000 metres the temperature will be -5 to 0 degrees Celsius, at 3000 metres around -7 degrees Celsius.

The risk of avalanches increases slightly with light snowfall.