Nock Mountains

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 moderate above around 2000 metres and low below. A soft snow surface and surface hoar are overlaid by strong southerly foehn with fresh wind slabs. Medium-sized slab avalanches can be triggered by individuals in some places, especially from north to east, but also in a few places in the west and south sectors. Fractures in the fresh wind slab can tear through the persistent weak layer and tend to propagate. Avalanche prone locations in the persistent weak layer are hardly recognisable and should be assessed defensively. Take particular care near transitions from a little to a lot of snow and in the blown-in entrance areas to steep gullies.

The snowpack is highly variable and areas with little snow alternate with considerable snowdrift accumulations. In general, there are a few centimetres of fresh wind slab snow on top of older, often hardness wind slabs, 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 of deep rime and angular forms, which are interspersed with further crusts in areas with more snow. The overall snow depth is well below average.

Strong foehn! Lively to strong southerly winds may soon reach the valleys and reach their maximum around midday. In the high alpine terrain of the northern Alps and in the typical foehn corridors, wind speeds of 60 to 80 km/h will be reached. Visibility is often limited only on the main Alpine ridge and in the Nockberge mountains, where a few snowflakes are possible in the afternoon. Temperatures at 2000 m from south to north between -2 and 2 degrees, at 3000 m around -6 degrees.

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