Lower Tauern South

Increasing avalanche danger due to fresh snowfall and strong-velocity winds

Increasing avalanche danger due to fresh snowfall and strong-velocity winds

Increase of avalanche danger during the daytime. As of late afternoon, danger above 1800 m will be CONSIDERABLE. As a result of northerly winds, fresh trigger-sensitive snowdrift masses will be generated. Danger zones in the morning are found on leeward slopes, esp. E/S ridgeline slopes above the treeline. Towards midday they will still be easy to recognize and should be avoided. In afternoon, the snowdrifts will increase in frequency and in size due to more fresh snowfall and strengthening winds. They will be generated in all aspects, also distant from ridgelines and at forest edges. Visibility will deteriorate, danger zones will become hard to spot. Medium sized avalanches can be triggered even by one sole skier. In addition, isolated weak layers inside the snowpack are prone to triggering. Least favourable are very steep shady slopes above 2200 m and sunny slopes at high altitudes (>2800m). As a result of the increased snow masses from last week these layers are ordinarily triggerable only by large additional loading. On very steep (>35°) sloeps or at rock precipices (transitions from shallow to deep snow), one sole skier can initiate fractures down to deeper snowpack layers. Avalanche releases are generally medium-sized.

As a result of NW winds on Monday, the loose snow will be transported, in the afternoon also the fresh fallen snow, and deposited on S/E ridgeline slopes. As winds intensify, also distant from ridgelines and deposited atop an unfavourable snowpack surface, then bond poorly with the snow beneath them. The middle part of the snowpack is generally quite compact and well consolidated. The lowermost part has weak layer prone to triggering on shady slopes abovbe 2200 m, on sunny slopes above 2800 m. Sometimes these are riddled with faceted crystals, sometimes with intermediate melt-freeze crusts. Near ground level there is depth hoar.

On Monday, storm-strength NW winds, gust in the afternoon will reach 100 km/hr. Initially, visibility will be adequate, but heavy cloud and snow showers in the afternoon will worsen it. At 2000 m: -6 degrees; at 3000 m: -9 degrees.

As a result of the cold front, snowfall by Tuesday morning, amid stormy winds: 10-15 cm, more from place to place. Winds will generate fresh, mostly small-sized snowdrift masses and remain prone to triggering.