Wölz Tauern South

Considerable danger of slab avalanches at high altitudes

Considerable danger of slab avalanches at high altitudes

With ascending altitude, avalanche prone locations swiftly become more frequent and danger rises from LOW to CONSIDERABLE. Main wind-loaded zones of freshly generated snowdrift accumulations are in extended eastern and southern aspects, small drifts behind protruberances or laterally in gullies are found also in other aspects. Triggering a slab avalanche is possible even by the weight of one sole person. Due to solar radiation and relatively high temperatures the fresh snow can settle, but also release as loose-snow avalanches in steep terrain. In the zones where snowfall has been heaviest, such avalanches can grow to large size.

The rounds of precipitation of recent days have left abundant fresh snow in the Northern Alps at high altitudes, e.g. on Tauplitz up to 50 cm of fresh snow was registered. On the northern flank of the Tauern and in Hochschwab as much as 30 cm. The fresh snow fell on a melt-freeze encrusted old snowpack surface, often blanketed by a thin layer of unbonded snowdrifts. Due to stormy NW winds there was massive snow transport and the freshly generated snowdrift accumulations are poorly bonded with the old snow. With rising SW winds on Thursday, also north-facing slopes will become drifted. At low altitudes the snow rapidly becomes wet, on sunny slopes it is moist up to high altitude.

An intermediate high on Thursday will being very favorable weather conditions. In the morning skies will be mostly cloudless, towards midday high altitude clouds will move in from the west, impede the sunshine somewhat. The initially strong westerly winds will ease, then shift to southwesterly, and foehn wind will arise on the northern flank of the Alps. In Tauern and Northern Alps temperatures will be mild. At 2000m: +2 degrees; at 1500m: +5 degrees at midday. On the southern flank of the Alps the temperatures will lie about 2 degrees lower. On Thursday night a cold front will strike the Eastern Alps but bring little precipitation. But temperatures in the Styrian Alps will drop noticeably. On the northern flank of the Alps, stormy NW winds will be blowing.

As temperatures fall, the moist snowpack will become firmer. Avalanche danger will recede.