Nock Mountains

Fresh, prone to triggering wind slab snow on a weak old snowpack

Fresh, prone to triggering wind slab snow on a weak old snowpack

The avalanche risk is moderate above around 1800 metres and low below. The situation is tricky for winter sports enthusiasts. A soft snow surface and surface hoar have been overlaid by strong southerly foehn with fresh wind slab. Up to 20 cm of new and wind slab snow is once again lying on top. Medium-sized slab avalanches can be triggered by individuals in some places, especially from west to north to east, but also in a few places in the southern sector. 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 barely recognisable and should be assessed defensively. Take particular care next to blown-off areas and neighbouring regions rated as "considerable".

Up to 30 cm of new fallen snow, most of which has been transported, lies 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 drift snow or 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 hardness melt-freeze crust.

Snow will fall in the Nockberge mountains tonight. In total, 20 to 30 cm of new fallen snow may fall at high altitudes (above approx. 1800 m), significantly less below. In addition, brisk southerly winds with peaks between 60 and 80 km/h will blow adjacent to ridgelines. Thursday will be mostly cloudy. Some snow will fall sporadically, with a maximum of 5 cm. In the afternoon it may clear up again from the west. The wind will still be blowing briskly from the south in the morning, but will then ease considerably. 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.