Increase in avalanche danger. Considerable avalanche danger will be encountered in some regions
Edition: 11.4.2021, 17:00 / Next update: 12.4.2021, 18:00
Snowpack
As a result of fresh snow and shifting winds, snowdrift accumulations which are prone to triggering are being generated in all aspects. They will increase in size and frequency during the course of the day. In the major areas of precipitation, the snowdrift accumulations will be large sized. In the central Valais and from northern Grisons into the Lower Engadine, where the least amount of snowfall is anticipated, they will remain small-to-medium sized.
In the more deeply embedded layers inside the snowpack in all regions, hardly any avalanche triggerings are to be expected.
Observed weather on Sunday, 11.04.2021
In the southern regions there was a small amount of snowfall above 1200 to 1500 m. In Grisons, skies were predominantly overcast but it remained dry. In the remaining regions of Switzerland north of the Main Alpine Ridge there were some foehn-induced bright intervals.
Fresh snow
Between Saturday evening and Sunday afternoon, the following amounts of fresh snow were registered above approximately 1800 m:
  • Simplon region, central sector of the southern flank of the Alps, Val Bregaglia, Val Poschiavo: 5 to 15 cm; in Val Bregaglia as much as 20 cm;
  • remaining regions of the Main Alpine Ridge from the Matterhorn to Bernina Pass: only a few centimetres;
  • in the remaining regions of Switzerland, it remained dry.
Temperature
At midday at 2000 m, between +5 °C in the western regions, +2 °C in the eastern regions, and -2 °C in the southern regions.
Wind
Winds were southerly.
  • Nocturnal winds were blowing at moderate to strong velocity over widespread areas;
  • during the daytime in the foehn-exposed regions blowing at moderate to strong velocity, otherwise at light-to-moderate strength.
Weather forecast through Monday, 12.04.2021
Frequent snowfall is anticipated. In the northern regions the snowfall level is expected to rapidly descend down to low lying areas during the nighttime hours. In the southern regions the snowfall level in the upper Alpine valleys will lie at approximately 1200 m; in southern Ticino it will incrementally descend from 1800 m down to 1400 m during the course of the day.
Fresh snow
Between Sunday afternoon and Monday afternoon, above approximately 2000 m:
  • furthermost western part of Lower Valais, central sector of the southern flank of the Alps, Rheinwald, Avers, from Val Bregaglia as far as Bernina Pass: 20 to 40 cm;
  • remaining parts of the northern flank of the Alps, remaining parts of Main Alpine Ridge from the Matterhorn as far as Bernina Pass: 15 to 30 cm;
  • remaining parts of the Valais and northern and central Grisons, Lower Engadine, Val Müstair: 5 to 15 cm.
Temperature
At midday at 2000 m, in the northern regions -7 °C, in the southern regions -2 °C.
Wind

  • Winds will slacken off during the nighttime hours and frequently be blowing only at light strength;
  • during the daytime at heightened altitudes blowing at moderate strength from northwesterly directions; in the western regions an increasingly strong bise wind will prevail; in the southern regions increasingly strong north winds.
Outlook through Wednesday, 14.04.2021
Tuesday
In the Valais and in the southern regions it will be quite sunny. In the northern regions a small amount of additional snowfall is expected to fall down to low lying areas, with the focus in eastern regions and Grisons. It will remain cold. Avalanche danger levels are not expected to change significantly.
Wednesday
On Wednesday it will be quite sunny. Avalanche danger is expected to incrementally decrease.