Gruyère

Considerable avalanche danger will be encountered over a wide area

Considerable avalanche danger will be encountered over a wide area

As a consequence of a moderate to strong bise wind, sometimes avalanche prone wind slabs formed. They are to be evaluated with care and prudence in particular in very steep terrain. Avalanches can in isolated cases reach medium size. Careful route selection is required.

Moderate to strong northeasterly wind will give rise to fresh snow drift accumulations that are prone to triggering, in particular in the Jura and the Prealps and at elevated altitudes. In addition, the fresh snow and snow drift accumulations of recent days remain prone to triggering. These layers are bonding only slowly with the old snowpack. Under the influence of warming and solar radiation, the snow that has remained loosely bonded and cold in many places will become more compacted. In consequence, the likelihood of avalanche releases in the fresh snow and snow drift accumulations will increase temporarily. From central Valais through northern Ticino to Grisons, in very isolated cases avalanches can also be released in the old snow at elevated altitudes. Fractures here will occur in faceted, loosely bonded layers either directly underneath the rain crust that formed at the end of December or deeper in the snowpack.

During the night, snow fell in the north, even at low altitudes. During the day, it was quite sunny in the west and south. In the east it was cloudy with bright spells and snow showers. Fresh snow: From Saturday afternoon until Monday afternoon the following aggregate amounts of snow fell: - Western Jura, extreme west of Lower Valais, regions north of a line between the Rhone and Rhine: 30 to 50 cm, but locally up to 70 cm - Eastern Jura, rest of Valais, rest of the Gotthard region: 15 to 30 cm - Northern Grisons 5 to 15 cm; smaller amounts or remaining dry elsewhere Temperature: At midday at 2000 m: about -9 °C in the north and -6 °C in the south Wind: During the night, mostly light. During the day in the south, light to moderate from the north. In the Jura and the Prealps, a strengthening bise wind. In the east a few further snowflakes will fall during the first half of the night. In the other regions the night will be mostly clear. During the day the weather in the mountains will be sunny. Fresh snow: - Temperature: At midday at 2000 m: between -2 °C in the west and -6 °C in the east Wind: - At elevated altitudes and in the south, strong from the northeast - In the Prealps and the Jura, a moderate to strong bise wind, otherwise mostly light winds

It will be sunny on Wednesday and Thursday. Temperatures will rise. On Thursday the midday temperature at 2000 m will be about +2 °C. There will be a moderate northeasterly wind at elevated altitudes, and in the Prealps and the Jura, in particular on Wednesday, a moderate to strong bise wind. The danger of dry avalanches will continue to decrease. Wet snow slides and gliding avalanches are to be expected on sunny slopes.