In the inneralpine regions a sometimes treacherous avalanche situation will prevail
Edition: 18.12.2021, 17:00 / Next update: 19.12.2021, 18:00
Snowpack
In the lower part of the snowpack, particularly on west-facing, north-facing and east-facing slopes above approximately 2200 m, weak layers are evident. In western Lower Valais and on the northern flank of the Alps these ground-level layers are covered over by thick layers of fresher snow so that the likelihood of avalanches being triggered by persons is low. From central Valais over the Ticino as far as Grisons, the snowpack layering is least favourable. In those regions isolated medium-to-large sized avalanches have been triggered by persons in the last few days.
The activity of gliding avalanches continues to diminish incrementally. Nevertheless, on steep grass-covered slopes which have not yet discharged, gliding avalanches continue to be possible in isolated cases. In the western and the northern regions where recent snowfall has been heaviest, these releases can grow to large size in some places.
During a night of clear skies on Saturday, a melt-freeze crust which is capable of bearing loads will form on the snowpack surface on very steep south-facing slopes. As a consequence of daytime warming and solar radiation, the snowpack surface on steep south-facing slopes will become moist
Observed weather on Saturday, 18.12.2021
It was sunny in the mountains during the daytime, following a night of clear skies.
Fresh snow
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Temperature
At midday at 2000 m, +5 °C.
Wind
Intermittently moderate-to-strong velocity northerly to easterly winds were blowing at high altitudes.
Weather forecast through Sunday, 19.12.2021
Following a night of clear skies it will be sunny in the mountains during the daytime.
Fresh snow
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Temperature
At midday at 2000 m, between +4 °C in the western and the southern regions and +1 °C in the eastern regions.
Wind
Winds in the central and eastern sectors of the Main Alpine Ridge and southwards therefrom will be northeasterly, blowing at moderate to strong velocity; in the other regions winds will be light to moderate.
Outlook through Tuesday, 21.12.2021
It will be sunny in the mountains on both days.
The danger of dry-snow avalanches is not expected to change significantly. As a result of lower temperatures, the activity of gliding avalanches will continue to diminish gradually.