Persistent weak layers
- All elevations
Old snow often weak on steep shady slopes. Isolated glide-snow avalanches.
Old snow often weak on steep shady slopes. Isolated glide-snow avalanches.
Favourable conditions prevail by and large. On high-altitude steep and shady slopes, weak layers at ground level can still be triggered in some places. Small-to-medium sized slab avalanches can be triggered especially by large additional loading in transitions from shallow to deep snow, e.g. at entries into gullies and bowls. In ridgeline terrain small fresh snowdrift accumulations require caution. In areas with âlowâ danger are isolated danger zones for dry-snow avalanches on extremely steep shady slopes. The peril of meing swept along and forced to fall require attentiveness. Particularly in regions where snowfall has been heaviest, isolated small-to-medium sized glide snow avalanches are possible on steep grassy slopes and hillsides which have not yet discharged. Cracks in the snowpack are signals of danger.
The snowpack on most steep slopes is well consolidated and stable, but on high-altitude very steep slopes there are frequently covered weak layers of faceted crystals which are triggerable. On north-facing slopes and zones where the solar radiation is flat, the uppermost layers are generally still loose and powdery, cold-induced. There is often surface hoar or a thin melt-freeze crust. At low and intermediate altitudes the snowpack is moist, which furthers the gliding movements of the snowpack. Small freshly generated snowdrifts in ridgeline terrain become more prone to triggering with ascending altitude.
Very sunny, frequently cloudless skies. In the evening, wide-ranging cirrus clouds will move in.Temperatures will rise palpably. At 2000 m: -4 to +1 degree. Light-to-moderate NW winds at high altitudes.
On Thursday, heavy cloud cover will create gray, gloomy visibility. Temperatures will rise. No significant change in avalanche danger.
Bulletin data: Avalanche Warning Service Vorarlberg (CC BY 4.0)