Wind slab
- Above treeline
Circumvent fresh snowdrift accumulations!
Circumvent fresh snowdrift accumulations!
A single winter sports enthusiast can trigger small slab avalanches in some places, particularly in ridgeline terrain and in wind-loaded gullies and bowls. If releases then sweep away deeper weak layers of the snowpack, the avalanche can in isolated cases grow to medium size. Danger zones are impossible to spot. Whumpf noises and fractures forming on the surface are alarm signals.
Storm-strength foehn winds generated trigger-sensitive snowdrift accumulations. They lie deposited atop loose snow or surface hoar in many places, or else atop a melt-freeze encrusted old snowpack surface. Particularly on steep shady slopes, the unfavorable snow base and intermediate layers of the snowpack have often persisted.
Thin layers of cloud cover widespread, little sunshine, diffuse light conditions. Winds will slacken off measurably. Temperature at 2000m: -1 degree; at 3000m: -7 degrees. Moderate-strength S/SE winds at high altitudes.
The likelihood of fresh drifts triggering will decrease only gradually. Unfavorable snow base and intermediate layers will persist.
Bulletin data: Avalanche Warning Service Vorarlberg (CC BY 4.0)