Wind slab
- Above treeline
Little new fallen snow.
Significant avalanche danger above the tree line! Avalanche prone locations difficult to recognise!
The avalanche risk is considerable above the tree line and moderate below it. During the night to Friday, fresh, unstable wind slabs will form in the north, west and south-east sectors, some of which will be covered by soft new fallen snow. The avalanche prone locations are therefore difficult to recognise and can also occur in unusual aspects. They are generally located on slopes that have been blown in, in terrain adjacent to ridgelines and at the entrances to gullies and bowls. Medium-sized slab avalanches can be triggered by a single person. Spontaneous slab avalanches are also possible.
Up to 50 cm of new fallen snow is expected from Thursday evening to Friday lunchtime, some of which will be transported by wind from various directions. The fresh wind slab may contain weak layers. The snow will often fall on bare ground. Where there is a snow base, fundament, it is crusted can form and hard. On steep meadow slopes, the snow can begin to glide.
From Thursday evening, it will snow throughout the Styrian mountains. After midnight, the snowfall level then drops everywhere down to the valleys. On Friday it will continue to snow frequently in the morning. A total of up to 50 cm of new fallen snow is expected in the foothills. The wind will initially be strong to gale-force from the south, turning from east to north-west during the night. The rising north-westerly wind will then bring increasing weather improvement in the afternoon and it may still clear up in places. The temperature at an altitude of 2000 metres will rise from -8 to -4 degrees during the day.
On Saturday and Sunday, a warm front will bring thick clouds and plenty of new fallen snow from the main ridge northwards. However, the snowfall level will gradually rise to an altitude of 1000 to 1400 metres. Increasing wet and sliding snow activity is expected from Sunday.
Bulletin data: Avalanche Warning Service Styria (CC BY 4.0)