Wind slab
- Above 1,600 m
Snowpack
On Monday with milder temperatures, new snow and drifted snow were deposited above approximately 1800 m on the still cold and often loose snow that fell last week. Along with often strong westerly winds, more snow will fall on Tuesday, especially in the west and north. During this precipitation spell, the fresh and drifted snow is likely to be easily triggered.
Deeper in the snowpack, there are faceted weak layers that are prone to triggering, especially on shady slopes above approximately 2400 m and generally in the high Alpine regions. Some avalanches may also release in these deeper layers.
Weather forecast to Tuesday
On the Main Alpine Ridge and north of it, it will be mostly very cloudy and further snow will fall, sometimes persistently so in the extreme west of Lower Valais and on the northern flank of the Alps. The snowfall level will drop to around 500 m.
South of the Main Alpine Ridge there will continue to be precipitation during the night, but during the day it will clear up with northerly winds.
Fresh snow
Until Tuesday afternoon, the following amounts will fall above approximately 1000 m:
Temperature
In the middle of the day at 2000 m, between -6 °C in the west and north and -3 °C in the south
Wind
Weather review for Monday
Conditions were mostly very cloudy. On Sunday evening, precipitation set in in the west and north. This was most intense in the extreme west of Lower Valais and along the Prealps, but the volumes were mostly below those forecast.
Fresh snow
The snowfall level was between 1600 and 1800 m in the west, 1200 to 1400 m in the east and below 1000 m in the south. The following amounts of snow fell above 2000 m:
Temperature
At midday at 2000 m, between 0 °C in the north and -5 °C in the south
Wind
Moderate to strong southwesterly wind at high altitudes
OutlookWednesday
In the north, snow will continue to fall in showers to below 1000 m, mostly from the eastern Bernese Oberland to the Alpstein region, where 15 to 30 cm is expected. Bright spells are possible, especially in inneralpine regions. On the southern flank of the Alps, it will be mostly sunny, with sometimes strong northerly winds extending down to the valleys.
The avalanche danger will decrease gradually in the west, but will increase slightly in the north and east. It will not change significantly in the south.
Thursday
The precipitation will end during the night into Thursday. During the day it will be quite sunny in the mountains in the north and mostly sunny in the south. The northerly wind will decrease appreciably.
The avalanche danger will decrease slowly.
Bulletin data: WSL Institute for Snow and Avalanche Research SLF (CC BY 4.0)