Lower Tauern South

Easily triggered snowdrifts at high/high-alpine altitudes

Easily triggered snowdrifts at high/high-alpine altitudes

Avalanche danger above 2200 m is considerable, below that altitude danger is moderate. Main problem: snowdrifts. Above 2200 m fresh snowdrift accumulations from Thursday and Friday, esp. on N/E/S facing slopes are prone to triggering. Avalanches can be triggered by 1 person in many places and reach medium size. Danger zones increase with ascending altitude. Above 2500 m, weak layers in the old snowpack can be triggered. Danger zones esp. on shady very steep slopes. Transitions from shallow to deeper snow are unfavourable. Releases usually require large additional loading but can fracture down to deeper layers and then grow to large size. Below 2200 m the gliding snow activity persists. Danger zones occur in all aspects. Glide-snow avalanches can release on steep grassy slopes and smooth rocky ground at any time of day and reach medium size. Avoid zones below glide cracks.

On Saturday the snowpack was able to settle somewhat and consolidate. Melt-freeze crusts dominate on the surface, or wind crusts in exposed terrain. Crests are completely windblown. Powder snow on shady wind-protected slopes (sink-in depths 10-50 cm). Snowdrifts from Thursday and Friday (in high alpine regions also on Saturday) were deposited on loose snow, the weak layer is mostly inside the fresh snow at the border to the old snowpack. In high alpine region above 2500 m the snowpack base still consists of crusts with soft embedded layers. Elsewhere the old snow base is very compact, even the crusts near ground level are well bonded. Since the snowpack is thoroughly wet at low/intermediate altitudes (the first snow was deposited on very warm ground) the entire snowpack can glide over smooth ground (grass, rocks) if the gradient is steep enough.

On Sunday, sunshine all day except for some harmless clouds. Good visibility. Light winds from varying directions (NW on Main Alpine Ridge at 30 km/hr). Very mild: 4-7 degrees at 2000 m, 0 degrees at 3000 m.

The warmth will help the snowpack to settle further, the snowdrift problem will diminish. The glide-snow avalanches will persist.