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Report
Thu. 07.12.2017
update 07.12.17 7:20 (Bernhard Niedermoser - translated by Jeffrey McCabe)

Latest snowdrifts easily triggered

Afternoon

Morning

Heading into backcountry requires a trained eye and disciplined restraint. Very steep drifted N/E facing zones should be avoided. Hoar beneath drifts is trigger-sensitive. Slab avalanche danger is MODERATE; above 2000 m CONSIDERABLE. Critical: gullies, bowls, very steep leeward slopes (distant from ridgelines), esp. edges of drifts and transitions. Isolated gliding avalanches below 2100 m.

Avalanche Danger

The hoar and the soft layers beneath the firm snowdrifts are the problem, creating CONSIDERABLE (3) slab avalanche danger above about 1900-2200 m; MODERATE danger below that altitude.

Potential avalanche prone locations lie above the treeline, esp. on NW-N-NE-E-SE facing slopes and in high alpine gullies in all aspects. Wind-loaded zones are near ridgelines, but also distant from them in exposed areas. Usually large additional loading is required for a release, but particularly at the edges of drifts, the weight of one person is sufficient.

Natural triggerings: sporadic gliding avalanches on extremely steep grass-covered slopes up to 2100 m continue to be possible.

Snow Layering

The snowfall and drifting from Monday/Tuesday has settled. In wind-exposed zones and in high alpine regions in general, wind crusts tend to dominate the scene. Exposed terrain is bare of snow, completely windblown. The drifts are relatively compact, were often deposited on a layer of hoar or loosely-packed powder. The proneness to triggering is slowly diminishing, but yesterday’s skier-induced releases prove that minimum additional loading is still enough to do the trick. In unskied terrain, settling noises can be heard. In high alpine regions, fresh snowdrifts accumulated yesterday anew.

Old snow: the layers below are favourably structured. Older layers are difficult to separate.

An ongoing risk: gliding snow masses below 2200 m, a result of early, mild snowfall (in November).

Alpine Weather Forecast (ZAMG Salzburg)

Sunshine today, and it will remain dry. Winds will be light up to 2200 m, further up and in the foehn lanes of the Tauern sometimes reaching 40-50 km/hr. At 2000 m, +2 degrees; at 3000 m, -4 degrees.

Tomorrow, Friday, high altitude clouds will move in during the morning. Starting at midday, intensifyig westerly winds will bring in heavy cloud cover. Light snowfall will set in. At 2000 m, temperatures dropping from +1 to -8 degrees; at 3000 m, from -6 to -16 degrees.

Short Term Development

The likelihood of avalanches triggering from older snowdrifts will diminish somewhat. In the afternoon, new snowdrifts will accumulate. The danger on Friday will be mostly MODERATE (2), in some isolated mountain massifs CONSIDERABLE (3). Very steep, wind-loaded zones should be avoided.





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