Gruyère

Snowpack

After some clear nights over the last few days, the surface of the snowpack is often angular and loose, except on steep south-facing slopes. There is also surface hoar in places. These surfaces are rather unfavourable for the new snow that is set to fall. With wind and little new fallen snow, small snowdrift accumulations are forming. These are prone to triggering.

Deeper in the snowpack, there are sometimes weak layers in the area of older rain crusts. However, these are often so deep in the snowpack that they are unlikely to be released by people. In southern Upper Valais, Ticino, Moesano, Val Bregaglia and Val Poschiavo, older weak layers are less covered and may occasionally be released by people.

Gliding avalanches are still to be expected, especially below 2400 m. These may become particularly substantial on the northern flank of the Alps and in Lower Valais.

Weather forecast until Wednesday, 20.12.2023

During the night, clouds will gather from the northwest, and light snowfall will start in the early morning in the north above approximately 800 m. During the day, snow will fall at times in the north. In Valais there will be longer bright spells. It will be fairly sunny in the south.

New fallen snow

Until Wednesday afternoon, the following amounts of fresh snow are expected above approximately 1200 m:

• northern flank of the Alps: 5 to 10 cm;
• other regions: less, and dry in the south.

Temperature

At midday at 2000 m, between +2 °C in the north and +5 °C in the south, dropping further in the afternoon.

Wind

• During the night, there will be strong westerly winds in the north at times.
• During the day, there will be strong northerly winds on the Main Alpine Ridge and south of it, otherwise mostly moderate from the northwest.

Weather review for Tuesday, 19.12.2023

It was sunny in the mountains.

New fallen snow

-

Temperature

At midday at 2000 m, around +7 °C, zero-degree level at over 3000 m.

Wind

Winds were mostly weak, becoming moderate from the southwest in the north as the day progressed.

Trend until Friday, 22.12.2023

On Thursday, snowfall will set in from the northwest, increasing as the day progresses. It will snow heavily in the north on Thursday night and during the day on Friday. The snowfall level in the north will be between 1000 and 1400 m. In the Alpine valleys in the east, snow will fall down to 600 m at times. It will be fairly sunny on the southern flank of the Alps on Thursday, but on Friday it will only be sunny in the far south. On both days, storm force west to northwesterly winds will blow at high altitudes.

Until Friday evening, 50 to 80 cm of snow will fall widely in the western Jura, in the extreme west of Lower Valais, on the Northern Alpine Ridge and in northern Grisons above approximately 1800 m, and from the Bernese Oberland to Liechtenstein in some places up to 100 cm. The avalanche danger will increase slightly on Thursday. On Friday, the avalanche danger in the regions exposed to heavier precipitation will increase further and reach danger level 4 (high) on a widespread basis. The avalanche danger will also increase in the other regions. The only place where it will not change significantly is in the south.