On wind-loaded slopes avalanches can fracture in ground-level layers
Weak layers in the old snow can be triggered particularly on wind-loaded slopes by one single winter sports enthusiast. The somewhat older snowdrift accumulations are easily recognized for the practiced tourers. Danger zones tend to increase in high alpine regions. Avalanches can be medium sized in isolated cases.
Avalanche headquarters have little information from high alpine regions. For that reason, the situation must be cautiously evaluated on-site. Apart from the risks of being buried in snow masses, the danger of being swept along and forced to take a fall need to be taken into consideration.
Snowpack
dp.1: deep persistent weak layer
The somewhat older snowdrift accumulations now blanket a weak old snowpack above 2200m. The upper layers of the snowpack are soft; the lower layers are faceted.
At all altitudes there is still little snow on the ground for this juncture of the season. The snowpack is highly irregular, even over small areas.
Avalanche danger above 2000m is moderate, danger is low below that altitude. Fresh and older snowdrifts can trigger a small-to-medium sized slab avalanche by minimum additional loading in some places. They are blanketed by just a bit of fresh snow, making them hard to recognize. Danger zones occur in all aspects and are often difficult to recognize. In addition, small moist loose-snbow avalanches can trigger in extremely steep rocky terrain.
Snowpack
A few centimetres of powder snow blanket the snowdrifted masses from the last few days. These drifts lie at 1800-2100m atop a melt-freeze crust which formed last Friday, under which a trigger-sensitve layer of faceted crystals has formed in some places. In addition, inside the old snowdrifted masses there are often weak intermediate layers. The old snowpack fundament is highly diverse in thickness, in exposed zones it is often lacking completely. At intermediate altitudes the fundament is often moist. On the surface at intermediate altitudes, a thin melt-freeze crust will form at night on sunny slopes, then be melted again once the sunshine strikees it tomorrow.
Tendency
Avalanche danger levels are expected to slowly recede.
Danger level
2400m
Avalanche Problem
Wind slab
2400m
At high and high-alpine altitudes, ridgeline snowdrifts demand caution.
Avalanche danger as of 2400m is moderate, danger is low below that altitude. Near ridgelines at high and high-alpine altitudes there are shallow drifts behind protruberances in the landscape behind ridges. Generally, large additional loading is necessary to trigger a small-sized slab avalanche in, sunny, steep rocky terrain, due to solar radiation, small loose-snow avalanches can trigger by large additional loading.
Snowpack
Loosely-packed fresh fallen snow is settling to an increasing degree, now covering older snowdrifts. At high and high-alpine altitudes the NE winds can transport the snow to ridgelines. At high and high-alpine altitudes the September snow has persisted and now serves as a compact base. In isolated cases these layers contain faceted crystals, they could serve as a fracture surface. The snow is distributed highly irregularly, ridges broad and narrow are often completely windblown, and even in other places the fresh fallen snow insufficiently blankets the snow base.
Tendency
Danger is expected to gradually recede.
Danger level
2000m
Avalanche Problem
Wind slab
2000m
With increasing altitude, snowdrifts demand caution
At higher altitudes the freshly-generated and older snowdrift accumulations are prone to triggering in some places, easily triggered as small-sized, in isolated cases as medium sized slab avalanches. Danger zones occur behind protruberances in the landscape, in gullies and bowls, and on freshly wind-loaded slopes. Magnitude and spread tend to increase with ascending altitude. Avalanche headquarters currently has little data from outlying regions about the snowpack, for that reason a cautious on-site evaluation is important. Below the treeline, avalanche danger is low. Isolated danger zone for small triggerings (slides) are possible in steep terrain. The risks of being swept along and forced to take a fall need to be considered.
Snowpack
The latest round of fresh snowfall was deposited atop a well consolidated old snowpack surface showing marked effect from the wind. Knolls and ridges are often totally windblown or have only a bit of fresh snow, gullies and bowls have noticeably more snow. With increasing altitude, particularly in pass and ridgeline areas, mostly small-to-medium snowdrift accumulations are evident. They are only moderate well bonded to the old snowpack surface, making them often prone to triggering.
Tendency
Currently, no significant change is expected.
Danger level
treeline
Avalanche Problem
Wind slab
Treeline
Caution urged towards small-sized snowdrifts
Above the treeline, fresh, mostly small snowdrift accumulations require caution. Isolated danger zones for small avalanche triggerings (slides) in steep terrain and freshly wind-loaded slopes are possible. Avalanche headquarters currently has little data from outlying regions about the snowpack, for that reason a cautious on-site evaluation is important. Below the treeline, no marked avalanche problem is evident.
Snowpack
The latest round of fresh snowfall was deposited atop a well consolidated old snowpack surface showing marked effect from the wind. Knolls and ridges are often totally windblown or have only a bit of fresh snow, gullies and bowls have noticeably more snow. With increasing altitude, particularly in pass and ridgeline areas, mostly small-to-medium snowdrift accumulations are evident.
Tendency
Currently no significant change is expected.
Danger level
Avalanche Problem
Gliding snow
Avalanche danger is low.
Avalanche danger is low, in isolated cases small drifts can trigger small sized slab avalanches by minimum addtional loading, e.g. the weight of one single skier. Also in steep, sunny, rocky terrain, small-sized moist loose-snow avalanches can unleash.
Snowpack
A few centimetres of loosely-packed powder snow now blanket a diversely thick but stable old snowpack. The fundament is often moist. On sunny slopes the surface snow is moistening and will form at night a thin melt-freeze crust which will melt again tomrrow as the sun hits it.
Tendency
Little change in avalanche danger levels is anticipated.
Danger level
Avalanche Problem
Wet snow
Snowpack
Tendency
Danger level
Snowpack
Tendency
Danger level
Avalanche Problem
Wind slab
Snowpack
Tendency
Danger level
Avalanche Problem
Wet snow
Avalanche danger in general low, small loose snow avalanche are to expect!
The Avalanche danger is in general low, but sun light and warming during the day will lead to destabilization of the small new snow layer. Spontaneous loose snow avalanches are expected especially from sunny slopes and extremely steep slopes.
Snowpack
The new snow from the weekend has settled. In high shady slopes the snow base is formed of faceted snow. The surface layer is built by loose new snow which will be unstable due to sunlight and warming especially on southern parts.
Tendency
The avalanche danger stays low.
Danger level
Avalanche Problem
Wind slab
Avalanche danger ind general low, small loose snow avalanches are to expect!
The Avalanche danger is in general low, but sun light and warming during the day will lead to destabilization of the small new snow layer. Spontaneous loose snow avalanches are expected especially from sunny slopes and extremely steep slopes.
Snowpack
South of the Alps low amount of snow which is loose and doesn’t cover the ground efficiently. In higher shady slopes the snow base is built of faceted snow. The surface layer is built by loose new snow which will be unstable due to sunlight and warming especially on southern parts.
Tendency
The avalanche danger stays low.
Danger level
Avalanche Problem
Wind slab
Avalanche danger is low, isolated danger zones due to small snowdrift patches
Avalanche danger is low. Fresh snowdrifts can be triggered in isolated cases as a slab avalanche by large additional loading. In extremely steep terrain, small-sized loose snow avalanches can release due to solar radiation.
Snowpack
The snow cover is settling to an increasing degree. It is not yet sufficiently thick for activities in outlying terrain.
