As a consequence of new snow a moderate avalanche danger will be encountered in some regions
Edition: 4.3.2021, 17:00 / Next update: 5.3.2021, 18:00
Snowpack
Fresh snow and freshly generated snowdrifts are being deposited atop rough, i.e. favourably structured old snowpack surfaces in many places.
In Grisons and in the Valais more than anywhere else, weak layers are evident in ground-level old snowpack layers above approximately 2200 to 2400 m in all aspects. However, during the last few days, no dry-snow avalanches have been triggered in these weak layers. Also stability tests have demonstrated that these layers are no longer likely to fracture or produce fracture propagation.
The snowpack on very steep south-facing slopes up to nearly 2800 m, on east-facing and west-facing slopes up to approximately 2200 m, is thoroughly wet. As a result of the cooler weather and overcast skies, no further process of the snowpack becoming wetter is taking place, so that only isolated gliding avalanches are still possible.
Observed weather on Thursday, 04.03.2021
In the eastern regions, nighttime skies were clear; in the western regions nocturnal skies were predominantly overcast. During the daytime in the Valais and in the Gotthard region, extensive sunny intervals were evident, in the other regions of Switzerland skies were overcast with a few bright intervals. In the northern regions there was a small amount of precipitation from region to region.
Fresh snow
In the northern regions above 1700 m, a small amount of snowfall was registered above 1700 m.
Temperature
At midday at 2000 m, approximately +1 °C.
Wind
Winds were light to moderate, blowing from westerly directions.
Weather forecast through Friday, 05.03.2021
During the night, precipitation is anticipated over widespread areas. During the daytime, precipitation is expected primarily in the central and eastern sectors of the northern flank of the Alps. The snowfall level will descend from approximately 1600 m down to 1000 m. During the course of the day in the Valais, it will become rather sunny, in the other regions of Switzerland skies will remain heavily overcast. In the southern regions it will be predominantly sunny and dry.
Fresh snow
By the end of this period of precipitation, the following amounts of fresh snow are expected:
  • northern flank of the Alps from eastern Bernese Oberland as far as Liechtenstein: 15 to 25 cm;
  • remaining parts of the northern flank of the Alps, Grisons north of Anterior Rhine, Prättigau: approximately 10 cm;
  • in the other regions of Switzerland, less; in the southern regions it will remain dry.
Temperature
At midday at 2000 m, between -4 °C in the northern regions and -1 °C in the southern regions.
Wind
  • Nocturnal winds will be westerly, temporarily blowing at strong velocity at heightened altitudes as the cold front passes through;
  • otherwise winds will be light to moderate from westerly directions; in the southern regions winds will be northwesterly.
Outlook through Sunday, 07.03.2021
Saturday
In the northern regions it will be predominantly sunny in the mountains. In the southern regions skies will be overcast for the most part. In central Ticino and in Sotto Ceneri, a few centimetres of fresh snow is expected above approximately 800 m. Winds will be blowing at light to moderate strength, to start with from northeasterly directions, subsequently from the west.
The main danger: dry-snow avalanches. In the northern regions the danger level will decrease, in the other regions no significant change in avalanche danger levels is anticipated.
Sunday
In the northern regions, skies will frequently be overcast, accompanied by sunny intervals in the eastern regions more than anywhere else. In the western regions, isolated showers are possible. In the Upper Valais, in the southern regions, and in Grisons, it will be quite sunny. It will be cool, accompanied by predominantly light-strength winds.
Avalanche danger levels are not expected to change significantly.