Persistent weak layers
- Alle Höhenlagen
Fresh snow/drifts and wet-snow avalanches
Fresh snow/drifts and wet-snow avalanches
Fresh drifts can trigger a medium slab or loose-snow avalanche by 1 person in wind-loaded gullies and bowls, and behind discontinuities; near-surface layers of often trigger-prone. Frequency and size of danger zones increase with ascending altitude. In case of extended bright intervals, medium-sized loose-snow avalanches are possible, possibly endangering exposed zones. Activities in outlying terrain demand experience in assessing avalanche dangers on-site. Danger rises during the course of each day due to warmth and solar radiation. Isolated glide-snow avalanches are possible. Increasing glide-snow avalanches on smooth grass-covered slopes which previously were bare. Avoid zones below glide cracks.
Fresh snow and drifts from previous days have settled and increasingly consolidated. Weak layers lie embedded in the latest fresh snow and drifts, these are prone to triggering. The snowpack is moist-to-wet down to the ground up to high altitudes, a thin melt-freeze crust often forms on the surface which then melts quickly. Because ski areas are closed there is little information about snowpack layering at high altitudes. At low and intermediate altitudes the lower layers of the snowpack are often wet, which reinforces gliding.
Nocturnal hours: Dry, mild, reduced nocturnal outgoing longwave radiation. Sunday daytime: High-altitude clouds, Sahara dust will hamper the sun somewhat. At 2000 m: +6 to +8 degrees. Strong to storm-strength southerly winds.
Foehn wind will persist, though slacken off somewhat. Sunny despite Sahara dust and very mild. In the southern ranges, more cloud cover. Danger of wet-snow avalanches will also rise during the course of each day. Backcountry skiing tours should begin early, end early.
Bulletin data: Avalanche Warning Service Vorarlberg (CC BY 4.0)