Persistent weak layers
- All elevations
Considerable danger of dry avalanches will be encountered in some regions. Wet avalanches during the day.
In some places avalanches can be triggered in the weakly bonded old snow and reach medium size. The avalanche prone locations are to be found especially on steep north facing slopes. Careful route selection is recommended.
As a consequence of warming during the day and solar radiation wet and gliding avalanches are possible. This applies in particular on east and west facing slopes below approximately 2400 m, as well as on south facing slopes below approximately 3000 m. Avalanches can reach medium size, especially on steep east facing slopes.
Snowpack In particular on north facing slopes over a wide area above approximately 2200 m, faceted weak layers exist in the snowpack. In Valais and on the northern flank of the Alps, these weak layers are mostly embedded deep. In some places here and in particular in areas where the snow cover is rather shallow, avalanches can still be released in these faceted layers of old snow. In Grisons and northern Ticino, these weak layers are closer to the surface. In particular in Grisons, they can still be released easily in some cases. Places in which avalanches can be released by people are slowly becoming less prevalent, but large avalanches still remain a possibility. The snowpack has already been penetrated by moisture to a large extent on south facing slopes, including up to high alpine regions. On west facing slopes as well, the snowpack has already become thoroughly moist up to approximately 3000 m. Thorough moistening is in progress on east facing slopes between 2200 and 2600 m, and on north facing slopes between 1500 and 1800 m. Observed weather review Tuesday, 21.03.2023 After a mostly clear night, the morning was mostly sunny. Clouds built up as the day progressed. Fresh snow - Temperature At midday at 2000 m: about +5 °C Wind Light, occasionally moderate, from westerly directions Weather forecast through Wednesday, 22.03.2023 During the second half of the night the skies will be clear. During the day it will be mostly sunny, but towards the evening cloud will build up from the west. Fresh snow - Temperature At midday at 2000 m: about +4 °C Wind Light to moderate from westerly directions Outlook through Friday, 24.03.2023 Thursday With mostly overcast skies on Wednesday night, the outgoing longwave radiation will be reduced. During the day there will be variable cloud with sunny spells. It will continue to become a little milder. The southwesterly wind will be moderate to strong and become stronger as the day progresses. In addition, a south foehn will develop during the day. The danger of dry avalanches will continue to decrease slowly. Some wet and gliding avalanches can occur, even in the morning. Friday Both during the night and in the daytime there will be variable to dense cloud cover. During the day there will be a little precipitation over a wide area. The snowfall level will drop from 2000 m towards 1500 m. The southwesterly wind will be moderate to strong. The danger of dry avalanches may increase a little in the regions exposed to precipitation. As a consequence of rain, wet snow avalanches can occur on north facing slopes in particular.
Bulletin data: WSL Institute for Snow and Avalanche Research SLF (CC BY 4.0)