Avalanche.report

Saturday 18.12.2021

Published 17 12 2021, 17:00


Danger level

2400m
Avalanche Problem
Persistent weak layer
2400m
Wind-drifted snow
Treeline


Weakly bonded old snow requires caution. Fresh wind slabs are to be evaluated with care and prudence.

Weak layers in the old snowpack can still be released by individual winter sport participants. Caution is to be exercised in particular on steep shady slopes above approximately 2400 m, as well as on steep sunny slopes in high Alpine regions. In particular transitions from a shallow to a deep snowpack are especially unfavourable. Remotely triggered avalanches are possible in isolated cases. In isolated cases avalanches are large. Whumpfing sounds and the formation of shooting cracks when stepping on the snowpack indicate poor snowpack stability. The avalanche prone locations are but are barely recognisable, even to the trained eye. Defensive route selection is appropriate.
The fresh wind slabs are in some cases prone to triggering, in particular on steep shady slopes above the tree line, as well as in all aspects at elevated altitudes.
On very steep sunny slopes wet and gliding avalanches are possible as the day progresses.

Snowpack

dp.6: cold, loose snow and wind
dp.1: deep persistent weak layer

Distinct weak layers in the old snowpack confirm the complex avalanche situation on steep shady slopes. In its middle, the snowpack is faceted and weak, in particular on shady slopes above approximately 2400 m, as well as on sunny slopes at elevated altitudes.
The fresh wind slabs will be deposited on the unfavourable surface of an old snowpack in particular on steep shady slopes at high altitudes and in high Alpine regions. As a consequence of mild temperatures and solar radiation the snowpack will consolidate.
Sunshine and high temperatures will give rise as the day progresses to slight moistening of the snowpack. As a consequence of mild temperatures a crust formed on the surface during the last few days.

Tendency

Weakly bonded old snow is to be avoided.


Danger level

2200m
Avalanche Problem
Persistent weak layer
2200m
Wind-drifted snow
2200m


Weakly bonded old snow is to be evaluated with care and prudence. Fresh wind slabs are to be avoided.

Avalanches can in some places be released in the weakly bonded old snow by a single winter sport participant, in particular on steep shady slopes at high altitudes and in high Alpine regions, as well as on steep sunny slopes in high Alpine regions. Mostly avalanches are medium-sized. Whumpfing sounds and the formation of shooting cracks when stepping on the snowpack indicate this situation. The number and size of avalanche prone locations will increase with altitude.
The fresh wind slabs are in some cases prone to triggering. Caution is to be exercised on steep shady slopes at high altitudes and in high Alpine regions.
On very steep sunny slopes gliding avalanches and moist snow slides are possible as the day progresses.
Careful route selection is recommended. Steep slopes are to be traversed by snow sport participants one at a time.

Snowpack

dp.7: snow-poor zones in snow-rich surrounding
dp.6: cold, loose snow and wind

Faceted weak layers exist in the centre of the snowpack, in particular on shady slopes above the tree line, as well as on sunny slopes at elevated altitudes. Field observations and snow profiles confirm this situation.
The wind slabs are in some cases still prone to triggering. They are poorly bonded with the old snowpack in particular on shady slopes. As a consequence of mild temperatures and solar radiation the snowpack will consolidate.
Sunshine and high temperatures will give rise as the day progresses to slight moistening of the snowpack. As a consequence of rising temperatures a crust formed on the surface during the last few days.

Tendency

Weakly bonded old snow requires caution. Fresh wind slabs require caution.