Persistent weak layers
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Snowdrifts at high altitudes, continuing wet-snow avalanches
Snowdrifts at high altitudes, continuing 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.
At high altitudes there are weak layers embedded in the snowpack, esp. on steep shady slopes, they are trigger-prone, as are freshly generated snowdrift accumulations. Despite high nocturnal clouds the outgoing longwave radiation is good, often forming a melt-freeze crust, softening quickly the next morning, causing the snowpack to forfeit its firmness. 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, good nocturnal outgoing longwave radiation. Monday daytime: High-altitude clouds, sunny but Sahara dust will hamper the sun somewhat. At 2000 m: +6 to +8 degrees. Moderate to strong southerly winds.
Foehn wind will continue, and intensify in strength. Sunny despite Sahara dust and very mild. In the southern ranges, more cloud cover. Avalanche danger is subject to a daily danger cycle. Backcountry skiing tours should begin early, end early.
Bulletin data: Avalanche Warning Service Vorarlberg (CC BY 4.0)