Rothenthurm

Especially on shady slopes above approximately 2400 m and generally in high Alpine regions, there are faceted, long-lasting weak layers deep in the old snowpack. In many places in western and northern regions with heavy snow, these layers are overlaid with deep fresh snow and so can no longer be easily triggered by winter sports participants. However, any avalanches that are triggered in these deep layers can still become large, as has been made clear by isolated avalanches over the weekend. In regions with less snow, avalanches can more easily be triggered in deep layers of old snow and will usually be of medium size.

With southerly winds, snowdrift accumulations prone to triggering will develop on Tuesday, especially adjacent to ridgelines.

Small to medium gliding avalanches are still to be expected in the west and north.

The night to Monday saw little but widespread snowfall. The snowfall level dropped from 1400 to 900 m. During the day, it was quite sunny in the mountains in the north and mostly cloudy on the southern flank of the Alps. Low stratus clouds lay over the Swiss plateau.

Fresh snow

From Sunday afternoon to Monday morning above approximately 1600 m:

• in the west and Lower Valais: 5 to 10 cm
• less elsewhere, dry in the south

Temperature

At midday at 2000 m, around -2°C

Wind

• Light overnight
• At times moderate to strong from southerly directions over the course of the day

There will be low stratus cloud in the north, with only occasional sunny spells in the west due to the broken, higher altitude cloud cover. Upper Valais via Central and Eastern Switzerland to Lower Engadine will see the most sun. Conditions will be cloudy on the southern flank of the Alps and a few flakes of snow may fall above approximately 1200 m.

Fresh snow

A few flakes are possible in the south.

Temperature

At midday at 2000 m, around -1°C

Wind

• Southerly, moderate at times during the night at high altitudes, rising to strong along the Main Alpine Ridge
• Mostly light during the day

Wednesday and Thursday will see low stratus cloud in the north, with sunny intervals above it. Conditions will be very cloudy in the south with up to 15 cm of snow falling over the two days above approximately 1200 m. Winds will be mostly light on Wednesday and mostly moderate on Thursday from southerly directions.

Avalanche risk will decrease in the north and increase slightly in the south with small amounts of fresh snow and with drifting snow.

Avalanches, possibly large, may still be triggered in places in the old snowpack, especially on steep shady slopes at high altitudes. Gliding avalanches are still possible in regions with deep snow in the west and north.