Rätikon West

Beware: fresh, trigger-sensitive snowdrifts

Beware: fresh, trigger-sensitive snowdrifts

Particularly in higher-altitude ridgeline and pass zones, as well as behind drops in the terrain, fresh snowdrift accumulations are extremely prone to triggering. One single winter sports enthusiast can trigger slab avalanches. Releases in the old snow are especially possible by large additional loading. If releases sweep away the entire snowpack, avalanches can grow to medium size. Danger zones occur particularly on steep shady slopes, but also in wind-loaded gullies and bowls in all aspects. Whumpf noises and fractures in the surface are alarm signals. Activities in backcountry demand careful evaluation of the terrain and the dangers.

The latest bout of fresh snow was intermittently transported by strong-velocity winds. Particularly in ridgeline and pass zones, freshly generated small-to-medium sized snowdrift accumulations occur. Especially where they are desposited on top of surface hoar or loose old snowpack layers, the bonding is poor. Small naturally triggered releases and fractures observed by others confirm the snowpack’s proneness to triggering. The old snowpack is overall unfavorably structured. Especially on steep shady slopes the weak intermediate layers and weak fundament have persisted.

Southerly foehn winds will generated dispersed clouds and some sunshine. During the course of the day the air will become moist, the clouds dense. Late in the afternoon light snowfall is anticipated in most regions. Temperature at 2000m: dropping from +1 to -4 degrees; at 3000m: from -5 to -8 degrees. Initially brisk southerly winds at high altitudes, later slackening off to moderate velocity.

Fresh snowfall and fresh snowdrifts will lead to slightly increased danger levels within the same Danger Level. The old snowpack continues to be weak.