Wind slab
- Above treeline
Weak old snow layers blanketed by drifts.
Weak old snow layers blanketed by drifts.
Marked weak layers in the old snowpack can still easily be triggered by one single winter sports enthusiast, especially above 2200m on steep, little-skied slopes. The danger zones are not visible. Remote triggerings are possible. Fresh snowdrift accumulations occur increasingly in ridgeline terrain and in wind-loaded gullies and bowls. Avalanches which release can fracture to deeper layers in the old snowpack and grow to medium size. Whumpf noises and fractures when treading on the surface are alarm signals. Activities in backcountry demand careful evaluation of the terrrain and assessment of the dangers. Restraint is advised.
Yesterday’s stormy winds generated trigger-sensitive snowdrift accumulations, deposited on top of a weak old snowpack surface above the timberline, often on loose snow or surface hoar (particularly on steep shady slopes). Avalanches triggered by winter sports enthusiasts confirm how prone to triggering the snowpack is.
Thin layers of cloud cover widespread, little sunshine, diffuse light conditions. In the Silvretta region, frequent fog. Winds will slacken off measurably. Temperature at 2000m: -1 degree; at 3000m: -7 degrees. Moderate-strength S/SE winds at high altitudes.
Weak layers in the old snow can still be triggered by one single winter sports enthusiast. The likelihood of fresh drifts triggering will decrease only gradually.
Bulletin data: Avalanche Warning Service Vorarlberg (CC BY 4.0)