As a consequence of warming and solar radiation a considerable danger of wet and gliding avalanches will be encountered over a wide area
Edition: 28.3.2021, 17:00 / Next update: 29.3.2021, 18:00
Snowpack
During a night of predominantly clear skies the moist snowpack will stabilize. On south-facing slopes a melt-freeze crust capable of bearing loads will be generated up to high alpine regions. As a result of daytime warming and solar radiation, the snowpack will subsequently forfeit its stability rapidly starting in the morning. Wet-snow and gliding avalanches are then to be expected, including large-sized releases.
In the uppermost third of the snowpck there is a marked weak layer evident in many regions. This layer is generally located near the layers of dust blown northwards from the Sahara desert and deposited in February. In the Valais and in Grisons more than anywhere else, isolated avalanches were triggered by persons in these layers during the last few days not only on north-facing, but also on east-facing, south-facing and west-facing slopes. These triggerings occurred predominantaly during the afternoon hours.
On high-altitude, steep north-facing slopes, most of the small snowdrift accumulations which generated on Friday can be triggered in places.
Observed weather on Sunday, 28.03.2021
On Saturday night skies were predominantly clear. During the daytime on Sunday it was mostly sunny.
Fresh snow
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Temperature
At midday at 2000 m, +4 °C in the southern Valais and in Ticino; and +2 °C in the remaining regions of Switzerland.
Wind
  • Winds in the northern regions were blowing predominantly at moderate strength from westerly directions during the nocturnal hours;
  • during the daytime hours, winds slackened off and were blowing mostly at light strength from the west.
Weather forecast through Monday, 29.03.2021
Following a night of clear skies it will be sunny and extremely mild.
Fresh snow
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Temperature
At midday at 2000 m, +7 °C, zero-degree level at 3300 m.
Wind
Winds will be light.
Outlook through Wednesday, 31.03.2021
In spite of isolated high-altitude cloudbanks, it is expected to be predominantly sunny and very mild. The winds will be blowing only at light strength. The zero-degree level will lie above 3000 m.
The danger of dry-snow avalanches will decrease. The avalanche situation is generally favourable in the early morning hours following nights of clear skies. The danger of wet-snow and gliding avalanches will increase significantly during the course of each day. On east-facing, south-facing and west-facing slopes, numerous naturally triggered avalanches can be expected. Skiing and freeriding tours in outlying terrain should be launched early in the day, and terminated early in the day.