Bollettino valanghe

Fresh snowdrifts more prone to triggering with ascending altitude

Fresh snowdrifts more prone to triggering with ascending altitude

Moderate avalanche danger at high altitudes, the main danger stems from freshly generated snowdrift accumulations. They become larger and more numerous with ascending altitude and are prone to triggering. One sole skier/boarder can trigger a small-to-medium sized avalanche in steep terrain. Naturally triggered loose-snow avalanches are possible in steep rocky terrain. In isolated cases avalanches can also trigger in the old snow. Such danger zones are found on very steep shady slopes in high alpine regions and on extremely steep slopes in general. Apart from the risks of being buried in snow masses the hazards of falling need to be taken into consideration.

There was 10-15 cm of new snow was registered widespread, in the Rätikon, Silvretta and Arlberg regions 20-25 cm. Amid intermittently strong winds the snow was transported and fresh snowdrift accumulations deposited behind protruberances, in gullies and bowls, frequently lying atop cold powdery layers of old snow on shady slopes. Bonding worsens with ascending altitude. The old snowpack is generally well consolidated and stable. Weak layers near the uppermost melt-freeze crusts as well as at mid-level of the snowpack can be triggered only in isolated cases in shady steep terrain and in high alpine regions.

From heavy cloud cover the snowfall will initially be light. The peaks will be veiled in fog. As of midday a bit of sunshine is possible in the wider valleys. Temperature at 2000 m: -12 degrees. Strong to stormy northerly winds at high altitude.

Saturday will be heavily overcast, accompanied by minor snowfall. Strong northerly winds will be blowing. Avalanche danger could rise somewhat at high altitudes.