Moderate avalanche danger will be encountered over a wide area
Edition: 27.3.2021, 17:00 / Next update: 28.3.2021, 18:00
Snowpack
As a result of small amounts of fresh snow and intermittently strong-velocity westerly winds, snowdrift accumulations have been generated. These drifts are predominantly small-sized in most regions. In the west, where most of the snowfall has been registered, they are somewhat larger-sized. The fresh snowdrift accumulations can be triggered on high-altitude north-facing slopes more than anywhere else.
In the uppermost part of the old snowpack there is a weak layer evident in many regions. In the southern Valais, in Grisons south of the Anterior Rhine and in the Gotthard region, isolated avalanches have been triggered by persons from this layer over the last few days. These triggerings occurred particularly on west-facing, north-facing and east-facing slopes, in isolated cases also on south-facing slopes.
During the nights of predominantly clear skies, the moist snowpack stablizes at intermediate altitudes. As a result of daytime warming and solar radiation, moist snowslide can be expected during the course of the day. On very steep slopes, gliding snow avalanches are possible.
Observed weather on Saturday, 27.03.2021
On Friday night there was a small amount of snowfall registered over widespread areas. The snowfall level in southern regions lay at 1600 m, in the northern regions it descended from 1800 down to 1200 m. During the daytime in the western regions, it swiftly become sunny at high altitudes. Also in the remaining regions of Switzerland, the snowfall came to an end. However, skies frequently remained overcast.
Fresh snow
Between Friday evening and Saturday midday, the following amounts of fresh snow were registered above approximately 2000 m:
  • Vaud and Fribourg Alps, furthermost western part of Lower Valais: 10 to 20 cm;
  • remaining regions of Switzerland: 5 to 10 cm over widespread areas, less in the southern Valais and in the Engadine.
Temperature
At midday at 2000 m, -3 °C in the northern regions and 0 °C in the southern regions.
Wind
  • Winds during nighttime hours were blowing mostly at moderate strength, intermittently at strong velocity, from southerly to southwesterly directions;
  • during the daytime blowing at moderate strength from westerly directions.
Weather forecast through Sunday, 28.03.2021
Following a night of clear skies it will be predominantly sunny on Sunday. In the furthermost southern regions it will be intermittently overcast in the morning hours in particular.
Fresh snow
-
Temperature
At midday at 2000 m, +4 °C in the western regions, +2 °C in the eastern and southern regions.
Wind
Winds will be light to moderate, blowing from westerly directions.
Outlook through Tuesday, 30.03.2021
In spite of temporary high-altitude cloudbanks passing through, it will be predominantly sunny and markedly warmer once again. Winds will be blowing only at light strength. The zero-degree level will lie at 3000 m.
The danger of dry-snow avalanches will decrease. The danger of wet-snow and gliding avalanches is expected to increase during the course of each day. Skiing and freeriding tours in outlying terrain should be launched early and brought to an end early in the day.