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 snowpacks as well as the weakly built-up old snowpack can be disturbed, whereby fractures can tear through. Avalanche prone locations are found in north-west, north to east facing steep terrain, but also in the south and west sectors and generally next to blown-off areas. They increase rapidly from the tree line upwards. Isolated remote triggering is still possible, drifting 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 local snow surface varies greatly. 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 sunny slopes. In addition, the wind slab begins to build up and is partially slightly moistened on the surface with sunlight. At the transition to the old snowpack, faceted crystals are deposited on and under the crust, which 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 deep rime. Ridges and ridges are often completely blown off.

During the night, the sky will be clear and in the open high-altitude areas of the Tauern, winds will continue to blow southeast to south at times with gusts of up to 60 km/h. On Wednesday, the sunny weather will continue with good visibility and dry air. The wind will be mostly light to moderate. The temperature at 2000 metres will be between -5 and +2 degrees, at 3000 metres around -6 degrees.

As the south foehn subsides, the wind slab problem is decreasing but the persistent weak layer problem remains.