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 on 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.
Snowpack
A small amount of fresh snow blankets older, generally somewhat stabilized snowdrift accumulations. The often lie deposited on loosely-packed snow at higher altitudes and atop a weak old snowpack surface (particularly on steep shady slopes). Avalanches triggered by winter sports enthusiasts confirm how prone to triggering the snowpack is.
Tendency
Weak layers in the old snow still prone to triggering
Danger level
1800m
Avalanche Problem
Wind slab
1800m
Persistent weak layer
Small amounts of fresh snow blanket small 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.
Snowpack
A small amount of fresh snow blankets older, generally somewhat stabilized snowdrift accumulations. The often lie deposited on loosely-packed snow or surface hoar or a melt-freeze encrusted surface. On steep slopes, unfavorable ground-level and intermediate layers inside the old snowpack persist in many places.
Tendency
Unfavorable snow base and intermediate layers will persist.
Danger level
2000m
Avalanche Problem
Wind slab
2000m
Persistent weak layer
2200m
Still a highly unfavorable snowpack
Older snowdrift accumulations can still be triggered. Marked weak layers in the old snowpack can be triggered by one single winter sports enthusiast, particularly on steep, little skied on slopes. The danger zones are not visible. 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.
Snowpack
A small amount of fresh snow blankets older, generally somewhat stabilized snowdrift accumulations. The often lie deposited on loosely-packed snow or surface hoar and atop a weak old snowpack surface at higher altitudes (particularly on steep shady slopes).
Tendency
Weak layers in the old snow can still be triggered by one single winter sports enthusiast.
