Wet avalanches are the main danger
Edition: 26.4.2021, 17:00 / Next update: 27.4.2021, 18:00
Snowpack
At high altitudes the snowpack is increasingly becoming moist all the way through: on south facing slopes below approximately 3000 m, on east and west facing slopes below approximately 2600 m, and on north facing slopes below approximately 2200 m.
On Monday it rained in some regions up to approximately 2100 m. Monday night will be mostly overcast and a little precipitation will fall in some regions again. The moist snow surface will not freeze in consequence and will not form a strong crust. Daytime warming will quickly reduce the stability of the snowpack in the morning, and the danger of both wet snow and gliding avalanches will increase.
In the last few days, only isolated wet snow and gliding avalanches have been reported. In the regions with a lot of snow, gliding avalanches can reach a large size.
Observed weather on Monday, 26.04.2021
In the west and south it was overcast and a little snow fell above approximately 2000 m. It was partly sunny in the north.
Fresh snow
From Sunday afternoon until Monday afternoon the following amounts of snow fell above 2500 m:
  • Valais, southern flank of the Alps, Upper Engadine: 5 to 10 cm
  • Elsewhere: a few centimetres or none
Temperature
At midday at 2000 m: between +5 °C in the west and +2 °C in the east
Wind
  • Mostly light, moderate at times, from the southwest
  • Along the Prealps, a light to moderate bise wind
Weather forecast through Tuesday, 27.04.2021
In the west and south during the night and in the daytime it will be very cloudy and a little precipitation will fall; above approximately 2000 m it will fall as snow. In the north there will be variable cloud and it will be mostly dry.
Fresh snow
From Monday afternoon until Tuesday afternoon the following amounts of snow will fall:
  • Valais, Vaud and Fribourg Alps and the southern flank of the Alps: 5 cm; high Alpine regions: up to 10 cm
  • Elsewhere: smaller amounts or none
Temperature
At midday at 2000 m: between +5 °C in the north and 0 °C in the south
Wind
  • During the night at elevated altitudes, light to moderate from the southwest, in the northern Alpine valleys there will be a foehn-like wind
  • During the day, light from westerly directions
Outlook through Thursday, 29.04.2021
Wednesday
Except in the east, it will be mostly very cloudy and a little precipitation will fall over a wide area. The snowfall level will be approximately 2000 m. As the day progresses, the southwesterly wind will strengthen in the north.
The danger of dry avalanches is not expected to change significantly. The danger of both wet snow and gliding avalanches will remain elevated.
Thursday
It will be very cloudy, and precipitation will fall over a wide area. During the day the snowfall level will drop from approximately 2200 m to 1600 m. The amounts of precipitation remain uncertain, but 20 to 40 cm of snow could fall in the extreme west of Lower Valais and in the western and central parts of the main Alpine ridge.
The danger of dry avalanches will increase, in particular in the regions where the precipitation has been heavy. The danger of both wet snow and gliding avalanches will remain elevated.