Waadtländer Voralpen

Snowpack

The surface of the snowpack has become faceted this week, especially on shady slopes. On Friday, small snowdrift accumulations will form in those northern regions exposed to the foehn wind and these will be prone to triggering.

The old snowpack varies from region to region:

• in those regions south of a line from the Rhone to the Rhine, there are weak layers in the lower part of the snowpack. These are particularly pronounced in Ticino, central Grisons, Engadine and the southern valleys of Grisons on wind-protected shady slopes and it is in particular here that avalanches may sweep away the entire snowpack. Even though the number of avalanches triggered has decreased, isolated, dangerously large avalanches have still been reported in the old snowpack.
• in those regions north of a line from the Rhone to the Rhine, avalanches are possible, especially in the upper part of the snowpack. Fractures in deeper layers of the old snowpack are unlikely here.

Gliding avalanches are still possible, and can be large in isolated cases.

Weather forecast to Friday

Mostly sunny in the north and partly cloudy but dry in the south.

Fresh snow

-

Temperature

At midday at 2000 m, between 0 °C in the north and -6 °C in the south

Wind

• In the north, increasingly moderate to strong south to southwesterly winds with foehn wind in the valleys
• Mostly weak in the south

Weather review for Thursday

Conditions were sunny in the mountains.

Fresh snow

-

Temperature

At midday at 2000 m, around +2 °C.

Wind

• In the Prealps and the Jura, strong bise wind in places
• Elsewhere weak to moderate winds, initially from the northeast, then from the southwest

Outlook

On Saturday and Sunday, conditions in the north will be brighter with the foehn wind. There will be heavy cloud cover in the south and 10 to 30 cm of snow will fall from Saturday afternoon to Sunday afternoon, although the amounts are still uncertain. The snowfall level will initially be at low altitudes and will increase to 1200 m on Sunday morning. The moderate to strong southerly foehn wind will die away overnight to Sunday.

Avalanche danger will increase from Saturday, with fresh snowdrifts in the north and new fallen snow in the south. Persistent weak layers will remain in Valais, Ticino and Grisons.