Weisseck, Muhr Valley

Considerable danger - small avalanches can fracture down to deeper layers

Considerable danger - small avalanches can fracture down to deeper layers

Avalanche danger above 1800 m is CONSIDERABLE, below that altitude danger is LOW. Restraint is important. Besides, visibility does not always permit clear assessment on-site. Main problem: snowdrift threat – the fresh foehn-induced drifts are highly varied with differing effects from valley to valley. Some are small and thin, often wide-ranging on freshly loaded slopes. The impulse of one persons is enough to trigger an avalanche (small-to-large). Experience is imperative. Danger zones are easily recognized. Second problem: persistent weak layer –hardly detectable from the snowpack surface. Potential weak layers inside the snowpack are likeliest in transitions into wind-loaded zones (often where snow is shallow). All in all the terrain has few spots where large additional loading (a fall, a group without distances, stomping) can trigger a slab avalanche. But if a slab triggers it can grow to large size.

The latest cold snow was transported somewhat by NW winds, small snowdrift accumulations were generated, mostly thin and not extensive. Beneath the new snow are compact layers with the dynamic forces well distributed. Inside the snowpack, particularly on north-facing slopes, are faceted crystal weak layers which could tend towards fracture propagation.

On Tuesday, dense cloud cover with snowfall will move in, visibility will deteriorate swiftly. Fresh snow in 24 hours: 5-10 cm. Winds will shift to NW and reach 30 km/hr. At 2000 m: -5 degrees. On Wednesday, adequate visibility to start with, a brief interim of sunshine, then cloud will move in, summits disappear in fog. Later in the afternoon/evening the next round of precipitation will arrive with strong-to-stormy westerly winds. Snowfall level: 1500 m. At 2000 m: from -4 to 0 degrees.

Snowdrift problem / Persistent weak layer. CONSIDERABLE danger (3). Caution: the new loading can fracture down to deeper layers and become large-sized avalanches.