Persistent weak layers
- Alle Höhenlagen
Danger zones in gullies and transitions where the snow is shallow
Danger zones in gullies and transitions where the snow is shallow
Avalanche danger above 2200 m is LOW. Caution is required in transitions in shady and high-alpine steep terrain, where large additional loading can trigger AN OLDER SNOWDRIFT MASS, then grow to a medium-to-large sized avalanche. Most danger zones are in W/N/E aspects distant from ridges and in steep gullies. The fresh snowdrifts in E/S/W facing ridgeline terrain are generally thin, the biggest risk is being forced to take a fall.
On shady wind-protected slopes there is settled powder atop a compact old snowpack. Near ridges the surface is wind-impacted, and these effects increase visibly with ascending altitude. On steep sunny slopes the snow is moistened up to intermediate altitudes, the nocturnally formed melt-freeze crust softens up. Hidden beneath the compact wind crusts are soft, faceted layers (persistent weak layer). These layers tend towards fracture propagation but are unlikely to trigger. In isolated cases there are initial sings of a near-surface COLD ON WARM problem on steep high-alpine sunny slopes (above 2600 m).
On Friday, initially sunny and cloudless weather. Starting at midday, convective clouds will increase but it is expected to remain dry, the visibility good. Cold northerly winds (30-40 km/hr) in exposed terrain. Temperatures will drop. At 2000 m: -10 to -7 degrees, at 3000 m: -17 degrees. On Saturday, intermittently sunny, temporary low lying clouds will hinder the visibility. Winds will shift to northeasterly, reach 30 km/hr. At 2000 m: -12 to -8 degrees; at 3000 m: -15 degrees.
No significant change is expected.
Bulletin data: Avalanche Warning Service Salzburg (CC BY 4.0)