Avalanche.report

Wednesday 11 December 2024

Published 10 Dec 2024, 17:00:00


Danger level

2100m
Avalanche Problem
Wind slab
2100m


At high and high-alpine altitudes, ridgeline snowdrifts demand caution.

Avalanche danger as of 2100m 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 addtional loading is necessary to trigger a small-sized slab avalanche in steep terrain. In steep rocky terrain, due to solar radiation, small loose-snow avalanches can trigger, medium-sized ones in regions where there has been heavy snowfall.

Snowpack

Loosely-packed fresh fallen snow lies deposited on last week’s snowpack surface (of snowdrifts and compacted snow). 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. Transition zones from the September snow to the November snow contain faceted crystals in isolated cases, these 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

1800m
Avalanche Problem
Persistent weak layer
1800m
Wind slab
1800m


Snowdrifts often lie deposited on weak old snow.

Avalanche danger above 1800m is moderate, danger is low below that altitude. Fresh and older snowdrifts are the major problem, these 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 near to ridgelines, in all aspects and in wind-loaded gullies and bowls. Frequency of avalanche prone locations tends to increase with ascending altitudes.

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.

Tendency

Avalanche danger levels are expected to slowly recede.


Danger level

2200m
Avalanche Problem
Wind slab
2200m


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.

Tendency

Snowdrift accumulations demand cautious assessment.


Danger level


Avalanche Problem
Wind slab


Snowpack

Tendency


Danger level


Avalanche Problem
Wind slab


Older snowdrifts often prone to triggering

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. Danger zones occur particularly in steep terrain near ridgelines on S/W/NW facing slopes and in wind-loaded gullies and bowls. They are covered by a small amount of fresh snow, thus are difficult to recognize. The risks of being forced to take a fall outweigh those of being buried in snow masses.

Snowpack

A few centimetres of loosely-packed powder snow now blanket small, older snowdrift accumulations on windward slopes. These drifts often lie atop trigger-sensitive intermediate layers. The old snowpack at high altitudes show marked effects of wind, the snow depths are highly varied.

Tendency

Little change in avalanche danger levels is anticipated.


Danger level


Avalanche Problem
Wind slab


Caution: older drift snow in higher alpine regions, especially in gullies and bowls with old snowpacks.

The Avalanche danger above around 2.000 m AMSL is moderate, below 2.000 m AMSL: low. Stormy winds from west to northwest cleared out exposed slopes but drifted snow towards gullies and bowls behind ridgelines. Snowdirftpacks tend to be prone to triggering, possible with bigger additional load. Danger spots are hardly visible due to new snowpack layers. Small to medium slab avalanches are possible.

Snowpack

The amount of new snow from Saturday is about 50 cm. The snow got on bare soils, fresh snow drift in gullies and bowls in highe shady slopes got on bonded snow from the last Novemberdays which transformed to facetted snow crystals. The bonding is weak. Little amounts of freshly fallen snow since Saturday causing hidden danger spots.

Tendency

Decreasing wind slab problem.


Danger level


Avalanche Problem
New snow


Snowpack

Tendency


Danger level


Avalanche Problem
Wind slab


Snowpack

Tendency


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
Wind slab


Small-sized loosely-packed snow avalanches are possible.

Avalanche danger is low. In extremely steep terrain, small-sized loose snow avalanches can release due to solar radiation. In isolated cases near ridgelines, there are freshly generated snowdrift masses which can, however, only trigger a slab avalanche in general by large additional loading.

Snowpack

Loosely-packed fresh fallen snow lies deposited atop a well settled and consolidated base or on bare ground. The snowpack is not sufficiently thick in all places for snow sports in outlying terrain.

Tendency

Danger expected to remain constant


Danger level


Avalanche Problem
Wind slab


Small Danger zones due to snow drifts

A few danger spots caused by freshly fallen drift snow layers on old snow packs from the last Novemberdays are located in shady slopes. Slab avalanches can only be triggered by higher additional loads. The scale of such avalanches would be small (sluff).

Snowpack

South of the Alps few snow, expected snowfall during the night predominately north of the Alps. Precipitations from the Italian low pressure system are expected only on the edges of the southern Alps with little amounts of snow and only few winds.

Tendency

No significant changes of the avalanche danger. Decreasing wind slab problem.