Wind slab
- Above treeline
- Size
- 2
Stability: poor · Frequency: some
Fresh and older snowdrift accumulations prone to triggering
Stability: poor · Frequency: some
Stability: very poor · Frequency: few
Fresh and older snowdrift accumulations prone to triggering
Avalanche danger levels above the timberline are moderate, below that altitude danger is low. Fresh and older snowdrifts can be triggered even by one sole skier. Danger zones occur particularly on steep shady slopes, in wind-loaded gullies and bowls and behind protruberances in the terrain. Size and frequency of danger zones tend to increase with ascending altitude. The snowdrifts are often blanketed, making them difficult to recognize. On steep grass-covered slopes, glide-snow avalanches are possible, particularly in sunny aspects. Caution urged below glide cracks.
On Thursday night, 15-25 cm of fresh snow was registered, in the Silvretta 10-20 cm, often transported by strong-velocity W/NW winds. The fresh snow and drifts were deposited atop an unfavorable, expansively metamorphosed old snowpack surface, often atop surface hoar, on shady slopes in particular. Also inside the snowdrifts themselves there are frequently trigger-sensitive intermediate layers evident. On sunny sloppes, bonding to the old snowpack surface is better. At high altitudes, weak layers near the ground and faceted intermediate layers inside the old snowpack can often be triggered.
Morning hours will be sunny, then clouds will move in above summit level. In the afternoon, clouds will become denser. By evening, cloud will be heavy even at lower altitudes. Temperatures will rise at all altitudes. At 2000m: from -12 to -4 degrees. Brisk westerly winds at high altitudes, in the evening strong-to-stormy.
Avalanche danger levels not expected to change significantly
Bulletin data: Avalanche Warning Service Vorarlberg (CC BY 4.0)