Zervreila

• Westernmost Lower Valais, northern Valais, Vaud Alps: A lot of the new and drifted snow is prone to triggering. It lies on an old snowpack with weak layers in places in the central part of the snowpack. With the end of the precipitation on Friday morning, the naturally occurring slab avalanche activity will be appreciably reduced. However, isolated naturally triggered avalanches may still become very large.
• Southern Valais, Ticino, Grisons: the old snowpack is very weak and contains distinct weak layers in the middle and lower part of the snowpack that are prone to triggering. Avalanches can easily be triggered by human activity in these layers and fractures in the snowpack can propagate over long distances. Avalanches may become very large, especially in southern Valais, where a lot of new snow and drifted snow is lying on the weak old snowpack from the last few days.
• Central and eastern parts of the northern flank of the Alps: there are also weak layers in the old snowpack in these regions. However, avalanches in these layers are less frequent and the main danger comes from the new and drifted snow. Below approximately 1800 m, the snowpack has been soaked by the sometimes intense rain.

Precipitation continued to fall in the west and north. Overnight to Thursday, the snowfall level was around 1800 m on the northern flank of the Alps and fell to 1200 to 1500 m in all regions during the day. In the Engadine, it was partly sunny in the late morning.

Fresh snow

From Wednesday afternoon to Thursday afternoon, the following amounts of fresh snow fell above approximately 2200 m:

• Westernmost Lower Valais, northern Valais: 40 to 60 cm;
• Rest of Valais, rest of northern Alpine ridge west of the Grimsel Pass: 20 to 40 cm
• Remaining western and central parts of the northern flank of the Alps, western Ticino: 15 to 30 cm; elsewhere less or dry.

In total, the following amounts of snow have fallen above 2200 m since the onset of precipitation on Tuesday:

• Westernmost Lower Valais, northern Lower Valais: 80 to 120 cm
• Vaud and Fribourg Alps, the rest of northern Lower Valais, the rest of the northern Alpine ridge west of the Grimsel Pass: 40 to 80 cm
• Remaining western and central parts of the northern flank of the Alps, western Ticino, southern Upper Valais: 30 to 50 cm
• Eastern part of the northern flank of the Alps, northern Grisons, rest of Ticino: 15 to 30 cm, less elsewhere

Temperature

At midday at 2000 m, around -2 °C

Wind

• Often strong southwesterly winds during the night
• During the day strong to storm force in the west and north, elsewhere moderate from west to northwest

During the first half of the night, heavy precipitation will continue to fall in the north. The snowfall level will be between 1000 and 1200 m. In the late morning, it will initially be quite sunny in all regions before clouds move in from the west.

Fresh snow

From Thursday afternoon to Friday morning above 1600 m:

• Western Jura, westernmost Lower Valais, northern Alpine ridge from Les Diablerets to the Tödi: 15 to 25 cm
• Rest of Lower Valais, rest of the northern flank of the Alps, northern Grisons: 10 to 15 cm
• Elsewhere less, dry along the central southern flank of the Alps

Temperature

At midday at 2000 m, around -2 °C

Wind

• Strong to storm force from the northwest during the night
• During the day moderate to strong in the west at high altitudes, otherwise light to moderate from the southwest

On Saturday, it will be very cloudy in all regions and there will be some precipitation at times; in the south this will occur mainly during the night, while in the north it will be during the day. The snowfall level in the south will be around 1000 to 1200 m, while in the north it will drop down to low altitudes. On Sunday there will be some more precipitation in the north with sunny spells in the afternoon. Conditions will be quite sunny in the south. There will be a strong to storm force northerly wind in the south overnight to Sunday.

The avalanche danger will decrease in the west, but will not change significantly in the other regions.