Nock Mountains

Fresh wind slab snow overlays persistent weak layer problem

Fresh wind slab snow overlays persistent weak layer problem

The avalanche risk is moderate above 1800 metres and low below. Especially in the sectors from north-west to north to south-east, slab avalanches can be triggered by individuals in some places. Avalanches that are triggered in persistent weak layers in deep weak layers or tear through these weak layers can reach medium size. Some avalanche prone locations are difficult to recognise and require a defensive route choice. In particular, be careful near transitions from little to more snow and in the snow-covered entrance areas to steep gullies.

New and wind slab snow cover a very different surface: in exposed areas it is marked by the wind, it is often encrusted and hard, only in high locations on shady slopes is it still soft. Within the snowpack, bonded snow overlays soft, angular layers. In wind-protected areas, on shady slopes above about 2000 m, on sunny slopes above 2400 m, surface hoar is also partly covered by snow. Breaks occur either in soft layers near the surface or around the crust that forms the transition to the completely built-up old snow foundation. In general, areas with little snow alternate in a confined space with sometimes considerable snowdrift accumulations and overall snow depths that are well below average. High temperatures and rainfall have moistened the snowpack up to around 2000 metres.

Clouds will be dense from the start on Saturday, but visibility will initially only be limited at high altitudes in the Tauern and Nockberge mountains. In the afternoon, the cloud base will drop and the mountains will become increasingly foggy. Light snowfall sets in. The snowfall level will initially be around 1400 metres and will fall during the day. By the evening it will snow 5 cm to a maximum of 10 cm north of the main Alpine ridge, less to the south. In the morning a brisk southerly wind will blow in the Tauern, during the day the wind will turn to the north and reach speeds of around 40 km/h in the evening. At 2000 m around -3 degrees, at 3000 m around -9 degrees.

The risk of avalanches increases with new fallen snow and wind.