Pre Alps

Fresh snow and snowdrift accumulations trigger-prone at high altitudes

Fresh snow and snowdrift accumulations trigger-prone at high altitudes

Fresh snowdrifts are the main danger. Danger zones occur in steep ridgeline terrain, behind discontinuities and in wind-loaded gullies and bowls and increase with ascending altitude. A small-to-medium slab avalanche or loose-snow avalanche can be triggered by 1 person (sometimes larger). Naturally triggered small slab and loose-snow avalanches in rocky steep terrain are possible. Glide-snow avalanches can trigger below 2600 m at any time of day or night and reach large size. Caution urged below glide cracks.

There is 20-30 cm of frsh snow lying atop soft layers or atop older snowdrifts on high-altitude shady slopes, otherwise atop a hard old snowpack surface. Intermittently strong SW/NW winds have generated new drifts. Bonding deteriorates with ascending altitude. Weak trigger-prone layers are evident inside the fresh snowdrift accumulations. Warm ground and the wet snowpack base reinforce the gliding movements of the entire snowpack. Frequent glide-snow avalanches have been reported. In zones where there has been rain impact the snowpack has been weakened.

Nocturnal hours: heavy rainfall/snowfall will spread, snowfall level initially at 1500-2000 m, dropping to 800 m or lower in early morning. Friday daytime: Snowfall in Vorderwald is already tapering off, the clouds are thinning, visibility improving. From Kleinwalsertal over Verwall to the Silvretta skies will remain gray, with light snowfall and reduced visibility. At 2000 m: -6 degrees. Westerly winds slackening off to moderate in the afternoon.

Saturday will be mostly dry and mild, isolated showers possible. Avalanche danger levels are not expected to change significantly. Glide-snow avalanches in particular are still possible.