Wind slab
- Above 1,800 m
Snowpack
In the west and north, layers of fresh and drifted snow from the last two days are lying on the thick layers of fresh snow from the past week, which are increasingly consolidating. Below this, in these regions the central section of the old snowpack contains weak layers in places. Avalanches triggered in near-surface layers can sometimes take these deeper layers of old snowpack with them and can become very large at times. This applies in particular to the northern Alpine ridge.
In Ticino, Grisons and some regions of southern Valais, the layers of new and drifted snow from the past week are thinner than they are further north. They are lying on an unstable old snowpack with pronounced weak layers. In these regions, human activity can still trigger avalanches very easily in the old snowpack, even from great distances. Avalanches may currently also be triggered in the treeline area or in sparse forest.
Gliding avalanches are increasingly possible on steep grassy slopes below approximately 1800 m.
Weather forecast to Saturday
It will be very cloudy north of the Main Alpine Ridge. It will continue to snow. During the night there will be only light snowfall, mainly in the east. During the day, snowfall will be widespread, and intense on the central and eastern parts of the northern flank of the Alps and in northern Grisons. Conditions will be mostly sunny south of the Main Alpine Ridge.
Fresh snow
The snowfall level will rise from 1000 to 1600 m. The following amounts of fresh snow are expected from Friday afternoon to Saturday afternoon:
Temperature
Rising, at midday at 2000 m between -2 °C in the north and +2 °C in the south
Wind
Northwesterly wind, increasing again
Weather review for Friday
It was overcast in the north. On Friday, it snowed until the early hours of the morning in particular, and especially on the northern flank of the Alps. The snowfall level was around 1000 m, and around 700 m on the eastern part of the northern flank of the Alps. In the south, it cleared up during the night and was quite sunny during the day.
Fresh snow
From Thursday afternoon to midday on Friday, above approximately 1200 m:
Temperature
At midday at 2000 m, between -4 °C in the north and +1 °C in the south
Wind
From the northwest
Outlook to Monday
On Sunday, it will be mostly sunny with denser clouds at times in the Jura, on the northern flank of the Alps and in northern Grisons. Winds will be light to moderate from westerly directions. On Monday, it will be mostly sunny on the southern flank of the Alps and in Valais. Otherwise, it will be generally very cloudy and some precipitation is possible, especially towards the east. The snowfall level will be around 1500 m. It will be appreciably warmer, especially in the south with +5 °C at midday at 2000 m. The avalanche danger will decrease, especially in western and northern regions with a lot of snow. Isolated naturally triggered avalanches are still possible on Sunday, especially on the central and eastern parts of the northern flank of the Alps and in northern Grisons. In southern Valais, northern Ticino and Grisons, the avalanche danger will decrease more slowly. Conditions for touring and off-piste skiing remain critical in many places here.
Bulletin data: WSL Institute for Snow and Avalanche Research SLF (CC BY 4.0)