Wind slab
- Alle Höhenlagen
Main danger: snowdrift accumulations prone to triggering; weak old snow at high altitudes.
Main danger: snowdrift accumulations prone to triggering; weak old snow at high altitudes.
As a result of fresh snow and strong-to-stormy W/NW winds, snowdrift accumulations are being generated in all aspects, frequently prone to triggering, mostly small. Danger zones occur near to and distant from ridgelines in steep terrain in all aspects and in wind-loaded gullies and bowls, behind abrupt discontinuities in the terrain. One person can trigger an avalanche, usually small-sized. In addition, superficial layers imn gullies and bowls, behind abrupt discontinuities in the terrain, and in transitions from shallow to deep snow can be triggered by large additional loading. Danger zones increase with ascending altitude in size and in frequency. If an avalanche fractures down to more deeply embedded layers in the old snowpack it can grow to medium size. Also, on steep, seldom-tracked shady slopes at high altitudes, deeper layers can be triggered by large additional loading. Apart from the risks of being buried in snow masses, the danger of being swept along and forced to take a fall also deserve consideration.
Fresh snowfall, strong winds, new trigger-sensitive snowdrift accumulations in all aspects. Winds have made ridges and crests bare of snow. In many places surface hoar had formed before the precipitation, now blanketed by the fresh snow. On south-facing slopes at high altitudes the fresh snow and drifts often lie atop a melt-freeze crust which is not capable of bearing loads; on north-facing slopes in wind-protected terrain atop soft layers and surface hoar. All in all, the trigger sensitivity of the snowpack has been raised. In ridgeline zone and pass areas, behind abrupt discontinuities in the terrain and in exposed zones, older snowdrift accumulations also occur. They are often inadequately bonded with the old snowpack surface or have weak intermediate layers. At high altitudes, esp. on steep shady slopes, there are often weak layers evident inside the snowpack. These spots are not visible to the naked eye.
Nocturnal hours: in the early part of the night, snowfall widespread extending down to low lying areas, plus stormy NW winds in the mountains. Tuesday: Initially still gray skies, often foggy, final snowfall. Swiftly dispersing clouds in the morning, some sunshine. Later, heavy cloud will move in from the north. At 2000 m: -5 degrees. Ongoingly strong NW winds.
Heavy cloud cover, light intermittent snowfall particularly in the northern regions. Strong to stormy W/NW winds. Avalanche danger levels are not expected to change significantly.
Bulletin data: Avalanche Warning Service Vorarlberg (CC BY 4.0)