Bisistal

In Grisons, the mostly clear nights are causing the surface of the snowpack to freeze to form a load-bearing crust at high altitudes, and the danger of wet and gliding avalanches is increasing over the course of each day. In other regions, nights are in some cases seeing reduced outgoing longwave radiation and isolated wet avalanches are possible throughout the day. The increasingly moist snowpack on north-facing slopes below approximately 2400 m is making wet avalanches especially possible in these locations.

Faceted weak layers in the old snowpack can in some cases still be triggered by human activity. Such danger zones are generally located at altitudes where the snowpack is becoming moist for the first time. Especially in central Valais and in Grisons, such avalanches can in some cases sweep away the entire snowpack, in particular on slopes with a thin snow cover.

In the east, there was patchy cloud during the first half of the night, with a continued small amount of precipitation. Elsewhere the night was mostly clear. Conditions were mostly sunny during the day.

Fresh snow

From midday on Friday into the night to Saturday, a few centimetres fell in the east above around 2300 m, with up to 15 cm in Lower Engadine.

Temperature

At midday at 2000 m in Valais around +10 °C, elsewhere around +7 °C

Wind

Light to moderate from westerly directions

During the night to Sunday skies will often be clear in Grisons, with patchy cloud elsewhere. During the day conditions will remain sunny for longer in Grisons, while other regions will often be cloudy. The afternoon will see light snowfall in the far west and on the main Alpine ridge in Valais above 2400 m.

Fresh snow

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Temperature

At midday at 2000 m around +5°C in the north and in Ticino and +7°C in Valais and Grisons.

Wind

Initially light to moderate southerly, becoming increasingly strong at high altitudes in the afternoon.

Monday

There will be heavy cloud cover, with snowfall especially in the south. The snowfall level will initially be around 2000 m, dropping temporarily to 1600 m during the course of the day. On the main Alpine ridge from the Great St. Bernard Pass to the Rheinwaldhorn and south of there, a widespread 20 to 40 cm of fresh snow is to be expected above around 2400 m, with as much as 50 to 80 cm falling in the heartland of the main Alpine ridge in Upper Valais. There will be a moderate to strong southeasterly wind.

Dry and wet avalanche danger will increase appreciably in the south. The danger level will probably rise to 4 (high) on the main Alpine ridge in Upper Valais. With heavy rain and snowfall at high altitudes, many naturally triggered avalanches are to be expected. On very steep west-, north- and east-facing slopes in particular, avalanches may in some cases entrain deeper layers of the snowpack, or the wet snow in their path, and may occasionally become very large.

In other regions, the danger of dry avalanches will increase somewhat with the southerly wind and fresh snow at high altitudes. Wet avalanches are still possible.

Tuesday

Tuesday will frequently be cloudy and showery. The snowfall level will be around 1700 m in the north and 2000 m in the south. Winds will mostly be light.

The danger of dry avalanches will decrease in the south. However, off-piste skiing conditions will remain critical at high altitudes. In the north, there will be hardly any change in dry avalanche danger. Wet avalanches are still possible in all regions, especially on west-, north- and east-facing slopes below approximately 2400 m.