Persistent weak layers
- Above 2,600 m
Snowpack
With the mild temperatures of the last two weeks, moisture penetration into the snowpack is already well advanced. At present, it is only increasing slowly. North-facing slopes at altitudes between 2200 and 2500 m are most susceptible to moisture penetration. On east- and west-facing slopes, the critical altitudes are somewhat higher, at approximately between 2500 and 2800 m. On south-facing slopes, moisture penetration into the snowpack extends as far as the high alpine regions. It is on these aspects and at these altitudes that isolated large wet slab avalanches may be triggered naturally.
In Grisons, the weak layers in the old snowpack are the least deeply buried, and it is here that wet slab avalanches are likely also to be triggered by human activity.
At higher altitudes, the snowpack is still dry. There are still weak layers in the old snowpack, but no more dry avalanches have been reported in recent days.
Weather forecast to Wednesday
In the far south, the night into Wednesday will be cloudy with some rain; it will become increasingly sunny during the day. In the north, it will be mostly sunny after a mostly clear night.
Fresh snow
-
Temperature
At midday at 2000 m, between +4 °C in the southwest and +1 °C in the northeast
Wind
Light.
Weather review for Tuesday
It was mostly sunny, and cloudy at times on the central and eastern parts of the northern flank of the Alps.
Fresh snow
-
Temperature
At midday at 2000 m, between +4 °C in the southwest and 0 °C in the northeast
Wind
Light to moderate from westerly directions
Outlook to Friday
After clear nights, it will be sunny during the day with light winds. The zero-degree level will be just below 3000 m on Thursday and will rise to around 3300 m on Friday.
The danger of dry avalanches will not change significantly. The danger of wet avalanches will increase during each day. Off-piste skiing and hut ascents should be completed in good time.
Bulletin data: WSL Institute for Snow and Avalanche Research SLF (CC BY 4.0)