Wind slab
- Above 1,800 m
Trigger-sensitive snowdrift accumulations blanket a weak old snowpack
Trigger-sensitive snowdrift accumulations blanket a weak old snowpack
Marked weak layers in the old snowpack can still easily be triggered by one single winter sports enthusiast, especially 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.
Recent 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). Reports characterize the persistent weak layer problem as less marked in Lechquellgebirge than in the southern regions of Verwall, Silvretta and Rätikon.
Following a heavily clouded night with hardly any precipitation, increasingly sunny mountain/skiing weather is forecast. Temperature at 2000m: -1 degree; at 3000m: -7 degrees. Light winds at high altitudes, increasingly from the south.
The likelihood of fresh drifts triggering will decrease only gradually. Weak layers in the old snow can still be triggered by one single winter sports enthusiast.
Bulletin data: Avalanche Warning Service Vorarlberg (CC BY 4.0)