Persistent weak layers
- Toutes altitudes
Persistent weak layer on shady high-altitude slopes
Persistent weak layer on shady high-altitude slopes
Above 2000 m, moderate danger prevails, below that altitude danger is low. Main problem: potential weak layers inside the old snowpack. Danger zones are located particularly on N/E facing slopes at entries to gullies and bowls and in transitions from shallow to deep snow. Weak layers inside the old snowpack can trigger from large additional loading. The snowpack is well bonded, potential slab avalanches can in isolated cases grow to large size, should they trigger. On steep wind-loaded slopes, naturally triggered glide-snow avalanches cannot be ruled out.
The expansive metamorphosis inside the old snowpack continues, the weak layers are becoming more pronounced particularly on shady slopes. The snowdrift accumulations deposited on top of those layers are well bonded and, particularly on south-facing slopes, are becoming moist during the course of the day. Thus, this uppermost layer can forfeit its firmness on steep slopes. In early morning the snowpack surface is melt-freeze encrusted due to outgoing nocturnal radiation.
On Saturday, residual clouds and fog will disperse from Eisenerzer to the Mürzsteger Alps already in the morning, sunny weather will then prevail. The very strong NW winds will ease. In the afternoon, clouds will move in from the west, but it will remain dry. Winds will shift to SW. At 2000 m: -4 to 0 degrees expected.
On Sunday, variably cloud conditions are expected, sunshine will prevail before a cold front brings initial snow showers to the northern flank of the Alps. Winds will shift to NW, temperatures will drop. Avalanche danger levels are not expected on Sunday.
Bulletin data: Avalanche Warning Service Styria (CC BY 4.0)