Persistent weak layers
- Above 2,200 m
Caution: marked weak layers in old snow
Caution: marked weak layers in old snow
Caution: marked weak layers in old snow: activities in backcountry demand cautious evaluation of the terrain and the dangers, as well as restraint. Avalanches which release can fracture to deeper layers in the old snowpack and grow to medium size. Such danger zones occur especially on steep shady slopes and are impossible to spot. Also remote triggerings are possible. Whumpf noises and fractures when treading on the surface are alarm signals. On sunny slopes, generally small loose-snow avalanches can trigger naturally during the course of the day. In addition, trigger-sensitive snowdrift accumulations will be generated during the day in foehn-exposed regions.
Older snowdrift accumulations from last week often lie deposited atop loose old snow at high altitudes, and a weak old snowpack, particularly on steep shady slopes. The snowdrift accumulations are often blanketed, making them impossible to recognize. Avalanches triggered by winter sports enthusiasts and fractures on the surface confirm how prone to triggering the snowpack is. During recent nights, surface hoar has formed in many places. The melt-freeze crust which has formed at lower altitudes softens up on sunny slopes during the daytime hours.
Sunny, good visibility. Rising southerly winds will be limited, feelable only in foehn-exposed lanes. Temperature at 2000m: -3 degrees; at 3000m: -9 degrees. Moderate to brisk SW winds, intensifying in afternoon and evening.
As a result of strong-to-stormy SW winds, avalanche danger will increase again at high altitudes.
Bulletin data: Avalanche Warning Service Vorarlberg (CC BY 4.0)