Wind slab
- Above 2,200 m
Snowpack
New snow and drift snow from the night to Friday will be deposited on unfavourable old snow surfaces and prone to triggering. On the northern flank of the Alps and in the west, some of these snowdrift accumulations are large, further south they are small to medium in size.
There are widespread weak faceted layers deep in the snowpack. North of a line between the Rhone and Rhine, these are often covered by thick, compact layers of snow. Avalanches in deeper layers may only be triggered in isolated cases and especially in places with little snow. In other regions, avalanches may still be triggered in weak layers near the ground and may still become large. There is little lying snow, especially along the Main Alpine Ridge in Grisons, in the Upper Engadine and in central Ticino, where avalanches may become medium in size.
In those northern and western regions with a lot of snow, medium and occasionally large gliding avalanches are still possible.
Weather forecast until Friday
Snow will fall during the night to Friday, mainly on the northern flank of the Alps. The snowfall level will drop rapidly at low altitudes. During the day, it will still be mostly cloudy along the Prealps and in the east with a final few flakes. It will be mostly sunny in Valais, Ticino and southern Grisons.
Fresh snow
From Thursday evening to Friday morning above approximately 1600 m:
Temperature
At midday at 2000 m, between -9 °C in the north and -4 °C in the south.
Wind
Weather review for Thursday
It was mostly cloudy. Snow began to fall in the afternoon, first in the Jura and later in the Prealps. The snowfall level has been around 1000 m.
Fresh snow
In the Jura, a few centimetres above approximately 1000 m.
Temperature
At midday at 2000 m, -1 °C in the north and -4 °C in the south.
Wind
Increasingly strong in the Jura and on the northern flank of the Alps, otherwise mostly moderate from the southwest.
Outlook
On Saturday, conditions will be sunny in the mountains at first. Snowfall will start in the afternoon in the west. The snowfall level will increase to around 2200 m during the night to Sunday. During the day there will still be a little precipitation in the east. Otherwise, there will be increasing clear intervals from the west and it will often be cloudy in Ticino. The zero-degree level will increase to 3000 m in the north and in Valais. From Saturday afternoon to midday on Sunday, a total of 5 to 15 cm of new snow will fall above approximately 2400 m on the northern flank of the Alps and in Valais, locally up to 20 cm. Moderate southwesterly winds will blow on both days, especially in the north and at high altitudes, with increasingly strong foehn winds from the south in the Alpine valleys on Sunday.
There will be hardly any change in the avalanche danger.
Bulletin data: WSL Institute for Snow and Avalanche Research SLF (CC BY 4.0)