Persistent weak layers
- Above 2,000 m
Prone to triggering wind slab on weak old snowpack. Many stones.
Prone to triggering wind slab on weak old snowpack. Many stones.
The avalanche risk is moderate above 2000 metres and low below. Slab avalanches can be triggered in a few places by low additional loads and can reach medium size if they tear through the old snowpack. Both fresh and older drift snowpacks as well as the weakly built-up old snowpack can be disturbed; fractures can also tear through into deeper weak layers. The avalanche prone locations increase rapidly from the tree line upwards. Drift snow areas and the transition from little to more snow should be consistently avoided. Whumpfing collapsing sounds when stepping on the snowpack can indicate danger.
On a locally very varied snow surface, there is partly soft new fallen snow, which is overlaid by fresh snowdrift accumulations in the daytime changes in the aspects from west to north to east. In general, there are often areas with little snow next to considerable snowdrift accumulations. The older snowdrift accumulations have been transformed in places to build up and are soft, in places hard as a board. The old snowpack consists of crusts with faceted crystals in between and deep rime. A break usually occurs around the uppermost crust. The total snow depth is well below average.
On Wednesday, dense high cloud fields will predominate in foehn weather, with visibility often limited in the highest regions, especially on the main Alpine ridge. In the afternoon, unproductive snow showers are possible along the Hohe Tauern main ridge. In the Tauern, stormy southerly winds (peaks 80 to 100 km/h, a little more in the morning) will blow in the high alpine areas. The wind will generally weaken slightly in the afternoon. Temperatures at 2000 metres will be around -3 degrees, at 3000 metres around -4 degrees. Snowfall will spread during the night to Thursday.
On Thursday, the foehn subsides, the prone-to-triggering wind slab is covered by fresh new fallen snow and is difficult to recognise.
Bulletin data: Avalanche Warning Service Salzburg (CC BY 4.0)