Nock Mountains

New and windslab snow on very weak old snowpack

New and windslab snow on very weak old snowpack

The avalanche risk is considerable above around 1800 metres and low below. The situation is precarious for winter sports. Heat input leads to a better formed slab. Medium-sized slab avalanches can be triggered remotely in some places, especially from west to north to east. This is particularly the case on the borders with neighbouring countries; inland, avalanche prone locations decrease with the amount of fresh snow. Fractures between new and windslab snow can tear through the persistent weak layer and tend to propagate. Avalanche prone locations in the persistent weak layer are barely recognisable and require a defensive choice of route.

Locally there is up to 30 cm of mostly soft new fallen snow on the wind-treated snow surface. Areas with little snow alternate with considerable snowdrift accumulations, some of which are as hard as a board and some of which are already being built up. Breaks usually occur between the fresh and slightly older layers of new or drift snow and near the crust that 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.

Friday will be mostly cloudy, with limited visibility at higher altitudes at times. In the afternoon, snowfall from the west and rain below around 1500 metres, but it will probably remain dry in Lungau. The wind will be weak to moderate from the west at all altitudes. Temperatures at 2000 metres will be around -2 degrees, at 3000 metres around -8 degrees.

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