Persistent weak layers· Morning
- Above 2,000 m
Daytime rise in wet-snow activity. Backcountry touring terrain: weak old snow.
Daytime rise in wet-snow activity. Backcountry touring terrain: weak old snow.
Well settled fresh snow and drifts blanket a weak old snowpack. Where the surface cannot bear loads, avalanches can be triggered even by one single winter sports enthusiast, esp. in little-skied terrain on west-, north- and east-facing slopes. Danger zones occur especially. in places where snow is shallow and in transitions from shallow to deep snow, as well as near ridgelines. Remote triggerings are possible. Avalanches can grow to large size, then flow over flat slope passages. Due to daytime warming and solar radiation, wet loose-snow avalanches can be expected, especially. on steep south-facing slopes below 2200m. On west and east-facing slopes where there is little now, these can fracture down to deeper layers and then grow to large size. On steep grass-covered slopes, glide-snow avalanches can release. Zones with glide cracks should under all circumstances be avoided.
The deep fresh snow and drifts of last week have settled well for the most part. Due to nocturnal outgoing radiation, a melt-freeze crust forms which is often capable of bearing loads on sun-exposed slopes up to 2200m. In the lowermost part of the snowpack widespread are large-sized cup-shaped crystals without any bonding. The unusual avalanche activity of last week confirms just how prone to triggering the old snowpack really is, and apart from heavily-skied routes this trigger-sensitivity persists in starting zones which have not yet discharged.
Very sunny, little wind and only thin cirrus clouds far above summit levels. Mild conditions continue, the zero-degree level at 3000m. Temperature at 2000m: rising from +6 degrees, at 3000m 0 degrees. Light to moderate southwesterly winds at high altitudes.
As a result of high-pressure weather conditions, the daytime rise in avalanche danger persists. The situation for winter sports enthusiasts remains treacherous in little-skied terrain.
Bulletin data: Avalanche Warning Service Vorarlberg (CC BY 4.0)