Persistent weak layers
- Above 2,200 m
- Size
- 2
Stability: poor · Frequency: some
Weak layers in the old snow are the major danger. Slides and small glide-snow avalanches due to higher temperatures.
Stability: poor · Frequency: some
Weak layers in the old snow are the major danger. Slides and small glide-snow avalanches due to higher temperatures.
At high altitudes, older snowdrift accumulations and weak layers are often still prone to triggering. Danger zones occur mostly on shady slopes behind protruberances in the landscape, in gullies and bowls and on wind-loaded slopes. Size and spread tend to increase with ascending altitude. Small-to-medium slab avalanches can be triggered even by the weight of one single skier. At low altitudes and particularly on sunny slopes, moist loose-snow avalanches and small-to-medium glide-snow avalanches can trigger due to the higher temperatures.
Older snowdrift accumulations lie deposited mostely on steep shady slopes atop expansively metamorphosed layers or atop surface hoar. Bonding to the old snowpack surface is only moderate, with increasing altitude. At high-altitude levels on shady slopes and in places where the snow is shallow, faceted layers are evident in the snowpack. All in all, snow depths are highly varied, ridges are often uttler windblown or with little snow, gullies and bowls are filled to the brim with snow.
During the nighttime hours, clouds will pass through intermittently, outgoing nocturnal radiation will be slightly reduced for that reason. On Wednesday, far-reaching cloudbanks will permit only reduced sunshine. Mild temperatures will continue. At 2000m: +6 degrees. Moderate to brisk westerly winds at high altitudes.
Older snowdrifts and old snow at high altitude are the main danger. At low altitudes and particularly on steep sunny slopes, slides and small glide-snow avalanches are possible.
Bulletin data: Avalanche Warning Service Vorarlberg (CC BY 4.0)