Zervreila

Near-surface layers on wind-protected shady slopes are lying on surface hoar in places. During the course of this week, snowdrift accumulations have formed in winds from varying directions, with Wednesday's strong winds being from the southeast. The snowdrift accumulations are particularly prone to triggering on shady slopes.

In the inneralpine regions of Valais and Grisons, the layers of fresh and drifted snow are additionally lying on a weak old snowpack with pronounced near-ground weak layers. Avalanches can sometimes propagate into these deep weak layers or be triggered there directly in isolated cases. In other regions, weak layers in old near-ground snowpack still remain in places on shady slopes but are now mainly so thickly covered that they are largely insensitive to triggering.

After a mainly clear night, conditions were mostly sunny, with broken cloud in the west and south. Cloud cover was thicker in places on the main Alpine ridge in Upper Valais. There was a light sprinkling of snow locally above around 1300 m, especially in the Simplon region.

Fresh snow

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Temperature

At midday at 2000 m, around 0 °C in the west and south and -3 °C in the east.

Wind

• Moderate north to northeasterly during the night
• Veering moderate to strong southeasterly on Wednesday morning, occasionally strong to storm-force along the northern Alpine ridge
• Occasionally moderate to strong foehn wind in the foehn valleys of the north
• Strong bise wind in the Jura

After a clear night, conditions will be sunny in the mountains. Cumulus cloud will develop during the day along the Prealps.

Fresh snow

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Temperature

At midday at 2000 m, around 0 °C in the north and -2 °C in the south

Wind

• Light to moderate northeasterly
• Light to moderate Bise wind in the Jura

Overnight to Friday, conditions will mostly be clear while during the day it will be sunny with broken cloud in the afternoon. There will be a light to moderate northeasterly wind. Overnight to Saturday, conditions will be partly cloudy, especially in the south, otherwise mostly clear. Variable cloud cover with sunny intervals and local showers is expected during the day. The snowfall level will be around 1200 m and the northeasterly wind will remain light to moderate. Saturday's weather conditions are, however, still uncertain.

The danger of dry avalanches will decrease. As daytime temperatures rise in the sunshine, the danger of wet avalanches will increase somewhat on steep sunny slopes over the course of each day. Isolated gliding avalanches will be possible.