Wind slab
- All elevations
Fresh snow and snowdrifts are prone to triggering
Fresh snow and snowdrifts are prone to triggering
Fresh snow and fresh snowdrifts are highly prone to triggering. Size and frequency of the danger zones increase with ascending altitude and during the course of the day. One person can triggered small-to-medium slab avalanches in gullies and bowls, behind abrupt discontinuities in the terrain.
More fresh snow plus strong W/NW winds will generate fresh snowdrift accumulations which are prone to triggering. Exposed ridges and crests are often windblown and bare of snow. Esp. intermediate altitudes evidence surface hoar. On south-facing slopes at high altitudes, often a breakable melt-freeze crust; on north-facing slopes in wind-protected terrain: surface hoar or soft layers. Bonding of fresh snow and drifts to the snowpack surface deteriorates with ascending altitude.
Nocturnal hours: heavily overcast skies, light snowfall in the mountains in particular (snowfall level at 600 m). Thursday: compact cloud cover, poor visibility, heavy snowfall (focus: Hinterwald, Arlberg, Verwall). Icy-cold NW winds will increase the subjective feeling of cold and generate snowdrift accumulations. At 2000 m: -6 degrees. Strong to stormy NW winds.
Friday will be quieter, with dispersed clouds. Avalanche danger will not change significantly.
Bulletin data: Avalanche Warning Service Vorarlberg (CC BY 4.0)