Considerable avalanche danger will be encountered in some regions. Fresh wind slabs require caution
Edition: 11.3.2021, 17:00 / Next update: 12.3.2021, 18:00
Snowpack
As a result of fresh snow and intermittently storm-strength westerly winds, the snowdrift accumulations will continue to grow in frequency and size during Thursday night. In the western and the northern regions they will be large-sized in some places, in the southern regions they will be small-to-medium sized. Fresh snow and freshly generated snowdrift accumulations are prone to triggering, particularly on north-facing and east-facing slopes.
In Grisons and in the Valais more than anywhere else, weak layers are still evident in the ground-level old snow above approximately 2200 to 2400 m in all aspects. Avalanches are currently unlikely to trigger in these deeply embedded weak layers of the snowpack.
Observed weather on Thursday, 11.03.2021
Following a night of partially clear skies there were extended bright intervals during the daytime hours. In the afternoon in western regions, heavy cloud cover moved in.
Fresh snow
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Temperature
At midday at 2000 m, between +5 °C in the Valais and in Grisons, +2 °C in the northern regions and -1 °C in the southern regions.
Wind
Winds in the northern regions and in the Valais were frequently blowing at moderate to strong velocity, in Grisons blowing at increasingly moderate to strong velocity, and in the Ticino predominantly at light strength, from westerly to southwesterly directions.
Weather forecast through Friday, 12.03.2021
On Thursday night, snowfall is anticipated over widespread areas. The snowfall level will swiftly descend from 1800 down to 1000 m. As morning approaches, skies are expected to clear up. In the northern regions skies will become increasingly overcast during the course of the day. In the southern regions it will remain rather sunny.
Fresh snow
By Friday morning the following amounts of fresh snow are expected above approximately 2000 m:
  • northern and furthermost western parts of Lower Valais: 20 to 40 cm;
  • northern flank of the Alps: 15 to 30 cm;
  • remaining regions of Switzerland and on the summits of the western Jura region: 5 to 15 cm over widespread areas.
Temperature
At midday at 2000 m, -5 °C in the northern regions and -2 °C in the southern regions.
Wind
Winds will be blowing from westerly directions,
  • frequently at strong-to-storm velocity during the nocturnal hours;
  • during the daytime hours in the northern regions and at heightened altitudes in general, blowing predominantly at moderate strength; in the southern regions at light to moderate strength.
Outlook through Sunday, 14.03.2021
Saturday
In the southern regions it will be quite sunny. In the eastern regions, foehn-induced bright intervals are anticipated during the morning hours. Otherwise skies will be predominantly overcast. During the course of the day in the northern and western regions, snowfall is expected above approximately 1000 m. In the north and at heightened altitudes in general, an increasingly stormy southwesterly wind will be blowing.
Avalanche danger levels are not expected to change significantly.
Sunday
In the northern regions, snowfall is expected above approximately 600 m. In the furthermost southern regions it will be quite sunny. A strong-velocity northwesterly wind will be blowing.
Avalanche danger levels will increase over widespread areas, most intensively in the northern and the western regions. Only in the furthermost southern regions will the avalanche situation remain generally favourable.