Freshly generated snowdrifts atop unfavorable old snowpack
Freshly generated snowdrift accumulations are prone to triggering, occur in steep terrain near to and distant from ridglines, behind drops in the landscape, in gullies and bowls in all aspects. Danger zones rapidly increase in frequency and in size with altitude above the timberline. Marked weak layers in the old snow can be triggered by winter sports enthusiasts, particularly on steep, little-skied on slopes. Avalanche prone locations are impossible to see, require a defensive route selection. Avalanches superficially triggered can fracture down to deeper layers inside the snowpack and grow to medium size. Whumpf noises and fractures on the surface are alarm signals.
Snowpack
As a result of fresh snowfall, fresh snowdrift accumulations which are prone to triggering are being generated. Focal point of precipitation is in the western barrier cloud regions to the Arlberg region and Allgau Alps: 10-15cm of snowfall plus storm-strength winds. Fresh snow and drifts will be deposited on top of an often melt-freeze encrusted surface, and surface hoar. Particularly on steep shady high-altitude slopes, markedly weak layers occur inside the old snowpack.
Tendency
Snowdrifts deposited on the weak old snowpack remain prone to triggering
Danger level
1800m
Avalanche Problem
Persistent weak layer
1800m
Wind slab
Treeline
Beware fresh snowdrift accumulations
Freshly generated snowdrift accumulations are prone to triggering, occur in steep terrain near to and distant from ridglines, behind drops in the landscape, in gullies and bowls in all aspects. Danger zones rapidly increase in frequency and in size with altitude above the timberline. Marked weak layers in the old snow can be triggered by winter sports enthusiasts, particularly on steep, little-skied on slopes. Avalanche prone locations are impossible to see, require a defensive route selection. Avalanches superficially triggered can fracture down to deeper layers inside the snowpack and grow to medium size.
Snowpack
As a result of some snowfall and storm-strength westerly winds, trigger-sensitive snowdrift accumulations will be generated. The small amount of fresh snow and drifts will be deposited on top of a frequently melt-freeze encrusted snowpack surface, sometimes with surface hoar. Particularly on steep shady slopes, unfavorable base and intermediate layers often occur inside the old snowpack, where they persist.
