Goldberg Group Central

Fresh trigger-sensitive drifts increasing at high altitudes: caution

Fresh trigger-sensitive drifts increasing at high altitudes: caution

Fresh snowdrift accumulations are often prone to triggering and difficult to recognize on Monday. Danger zones occur in gullies and bowls above 2300 m on NW/N/SE facing slopes, increase with ascending altitude, mostly medium-sized. Gliding snow activity will remain upright. Danger zones occur in all aspects up to 2400 m. Glide-snow avalanches can trigger anytime on steep grassy slopes and smooth rocky ground, and reach medium size. Avoid zones below glide cracks. Above 2600 m, weak layers in the old snowpack can be triggered. Danger zones occur esp. on shady slopes in transitioins from shallow to deeper snow, triggering usually requires large additional loading. Superficial releases (drifts) can fracture down to more deeply embedded layers of the snowpack, in isolated cases grow to large size. Due to rain impact and mild temperatures, small wet-snow avalanches are possible on extremely steep slopes at low and intermediate altitudes.

Fresh snowdrift accumulations esp on shady high altitude slopes lie atop a loose snowpack and are prone to triggering there. On smooth ground (grass, rocks) which are steep enough, the entire snowpack can glide. The lowermost part of the snowpack has numerous melt-freeze crusts between which are faceted crystals, esp. on north-facing slopes and at high altitudes. The weak layers are most prevalent on shady slopes with shallow snow.

On Monday, visibility initially reduced due to fog and precipitation. Snowfall level at 1500 m, heavy showers will bring 10-20 cm of fresh snow at high altitudes by noon. Towards the end of this bout of precipitation, winds will slacken off, be blowing mostly at moderate strength from the west. In the afternoon, dry weather conditions. At 2000 m: -5 to 0 degrees; at 1000 m, 0 to +4 degrees, at 3000 m, -5 degrees.

Avalanche danger will not change.