Gruyère

Considerable avalanche danger will be encountered over a wide area.

Snowpack

Above the tree line, there is about twice as much snow as is normally the case at the end of November. Only in the south are the snow depths below average. In the central part of the snowpack there are various melt-freeze crusts and, in between, thin layers of angular crystals. A number of avalanches have been released in these weak layers in the past few days, and this is expected to increase with the freshly fallen snow and the rise in the temperature. The southwesterly wind has moved a lot of this new snow. Below around 1500 to 2000 m, the snowpack has become moist and weakened because of rain.

Weather forecast through Friday, 01.12.2023

It will be very cloudy. There will be widespread precipitation, most of it during the night in the far west and in the afternoon in the Bernina region. In the north, the snowfall level will be around 2000 m during the night, dropping to 1000 m during the day. In the southeast, however, the snowfall level will increase to around 2000 m during the day.

Fresh snow

From Thursday afternoon to Friday afternoon, snow will fall above approximately 2400 m:

• the far west of Lower Valais on the border with France, the Bernina region: 30 to 40 cm;
• the far west of Lower Valais, northern Upper Valais, the western part of the northern flank of the Alps, the northern part of Central Switzerland, the eastern Prealps, Avers, Val Valais, Val Poschiavo: 15 to 30 cm;
• elsewhere: to a lesser extent.

Temperature

At midday at 2000 m, widespread at -3 °C, in the southeast at 0 °C.

Wind

Strong at altitude, otherwise weak to moderate from the southwest.

Observed weather review Thursday, 30.11.2023

It was very cloudy, and precipitation set in during Wednesday night. At first, snow fell even in the lowlands. The snowfall level then rose to around 1800 m in many places. In the south, it remained at low altitudes.

Fresh snow

Until Thursday afternoon, fresh snowfall was registered at altitudes of approximately 2000 m and above:

• Lower Valais and northern Upper Valais: 30 to 40 cm, 50 cm on the border with France;
• southern Upper Valais except the upper Visp valleys, Val Bregaglia, Val Poschiavo and the eastern Jura above 1000 m: 15 to 30 cm;
• elsewhere: to a lesser extent.

Temperature

There were warm incoming air flows at altitude, while colder air remained for longer further down:

• At midday at 2000 m, between +2 °C in the far west and -4 °C in the inneralpine regions and in the south.

Wind

Moderate to strong, in places a stormy southwesterly wind at high altitudes.

Outlook through Sunday, 03.12.2023Saturday

It will be very cloudy with snowfall, including at low altitudes. On the eastern part of the northern flank of the Alps and in Grisons, the forecast is still very uncertain and even greater depths of new, freshly fallen snow are possible. Elsewhere, 5 to 15 cm will be common. As the day progresses, it will become sunny in the far south with strong northerly winds. The avalanche danger will decrease in the west. On the eastern part of the northern flank of the Alps and in Grisons, it may increase depending on the amount of fresh snow, maybe particularly in the Bernina region. In the other regions, the avalanche danger will not change significantly.

Sunday

It will be mostly sunny, but cold. The northwesterly wind will die down during the night. Even though the avalanche danger will decrease, the situation will to some extent remain precarious for off-piste winter sports.