Wind slab
- All elevations
Snowdrift problem above 2400m. Glide-snow avalanches, daytime wet-snow avalanches below 2200m.
Snowdrift problem above 2400m. Glide-snow avalanches, daytime wet-snow avalanches below 2200m.
Older snowdrift accumulations are prone to triggering above 2400m, can be triggered, make a prudent route plan indispensable. Avalanche prone locations are found in steep terrain in all aspects, behind protruberances and in wind-loaded gullies and bowls. If avalanches fracture down to deeper layers of the snowpack they can grow to dangerously large size. Below 2200 m medium-sized (in isolated cases large-sized) glide-snow avalanches are possible. Caution on slopes where there are glide cracks. As a result of solar radiation and daytime warming, wet slides and avalanches can release during the course of the day, particularly on sunny slopes.
The snowpack shows the effects of rain and wind from the last few days. Up to 2200m it is thoroughly wet, up to 2500m it is moist. During nights of clear skies, a melt-freeze crust forms below 2500m which is capable of bearing loads. The rain and mild temperatures have helped the snowpack to quickly settle. At high altitudes where there was no rain (above 2400m) the snowpack is stabilizing more slowly. Through stormy W/NW winds the snow was intensively transported on both days, new snowdrift accumulations formed. Brisk to strong W/NW winds have generated snowdrift accumulations at high and high-alpine altitudes which are prone to triggering. The transported snow was deposited on wind crusts, melt-freeze crusts or atop older snowdrifts, on high altitude shady slopes also on loose, powdery layers, making it prone to triggering. On south-facing slopes, bonding to the old snowpack is better. In addition, on very steep high-altitude shady slopes there are weak layers at mid-level inside the snowpack in some places: they are prone to triggering. Due to the dryness of the air, the snowpack surface softens little on sunny slopes, in the other aspects it remains hard and dry, thus reducing avalanche activity to a minimum.
A high-pressure front determines weather conditions today. The sub-tropical air remains dry and warm, sunshine all day long. At the edge of this front, the NW wind will be stronger than it was yesterday, but will soon slacken off. Temperature at 2000 m: +9 degrees. Brisk to strong NW winds at high altitude, easing later on.
Following a night of clear skies, Sunday will be mild and partly sunny. Avalanche danger is subject to a slight daytime cycle.
Bulletin data: Avalanche Warning Service Vorarlberg (CC BY 4.0)