Allgäu Alps Central

Numerous natural triggerings of wet-snow avalanches expected

Numerous natural triggerings of wet-snow avalanches expected

Avalanche danger in the Allgäu Alps is considerable. Main problem: wet snow. Naturally triggered wet loose-snow and slab avalanches can be expected on steep slopes at intermediate altitudes, often reaching medium size but with large runout zones. Exposed transportation routes can be placed at risk. In additional, snowdrifts are a problem at high altitudes. Danger zones are numerous, occur in steep ridgeline terrain on NW/N/SE facing slopes, behind discontinuities and in wind-loaded gullies and bowls. Snowdrift accumulations can be triggered as slab avalanches by one sole person and reach medium size.

Rising temperatures and heavy rainfall will make the surface wet, the moisture will seep deep into the snowpoack, leading to a loss of firmness and instability of loose snow. In additional the water can remain stored on the the melt-freeze crusts and destabilize further the weak layers. At highest altitudes the snow will be transported by foehn winds and deposited on north-facing slopes as snowdrift accumulations atop the cold loose layers of snow. The layering at high altitudes is poor: weak intermediate layers are in the uppermost part (graupel) and faceted layers between wind crusts and near thin melt-freeze crusts are deeper down. At the bottom level the snowpack is compact and stable.

The wet-snow avalanche activity will be high on Thursday, then on Friday temperatures will drop.