Gruyère

In the west and in the south a considerable avalanche danger will be encountered over a wide area.

The new snow and wind slabs of the last two days are prone to triggering. They are lying on top of a weakly bonded old snowpack on west to north to southeast facing aspects. Avalanches can in some places be released easily and reach medium size. The avalanche prone locations are to be found especially in gullies and bowls. Backcountry touring and other off-piste activities call for careful route selection.

Snowpack At elevated altitudes in the furthermost western regions and in the Ticino, the amount of snow on the ground corresponds to annual averages for this juncture of the season, in all the other regions of Switzerland there are less than average amounts of snow on the ground. At 2500 m the snow depths in the western regions, as well as from the Simplon region over Goms into the Gotthard region and in the central sector of the southern flank of the Alps, amount to approximately 80 cm. In the remaining regions of Switzerland there is 40 to 60 cm over widespread areas, less in the central part of Valais.Particularly on shady slopes above approximately 2200 to 2400 m, there are weak, expansively metamorphosed (faceted) layers evident inside the snowpack over widespread areas. These layers in the western regions, and on the Main Alpine Ridge from the Matterhorn into the Bernina region and southwards therefrom, are already blanketed over by so much snow that even dangerously large-sized avalanches are possible.The freshly generated snowdrift accumulations have been deposited on top of an unfavourable old snow cover and are prone to triggering for that reason. In the southern regions there is lots of loosely packed snow deposited on the upper surface which is being transported by strong-velocity northerly winds. Observed weather review Saturday, 10.12.2022 In the southern Upper Valais and in the Ticino it was predominantly sunny, in the remaining regions of Switzerland skies were heavily overcast and there was snowfall registered down to low lying areas. Fresh snow Between Friday afternoon and Saturday afternoon the following amounts of fresh fallen snow were registered above 1000 to 1500 m:

• Northern flank of the Alps west of the Reuss, northern and western Lower Valais: 10 to 20 cm; 30 cm in the Trient region;
• remaining regions of Switzerland: as much as 10 cm.

Thus, since the beginning of this period of precipitation on Thursday, the following overall amounts of fresh snow have been registered:

• Vaud Alps, Oberland west of the Diemtigtal, furthermost western part of Lower Valais, northern Lower Valais: 30 to 40 cm; on the French border as much as 50 cm;
• remaining parts of the western sector of the northern flank of the Alps, remaining parts of Lower Valais, northern Upper Valais, Sotto Ceneri, Upper Engadine, Val Bregaglia and Val Poschiavo: 15 to 30 cm;
• remaining regions of Switzerland: as much as 15 cm.

Temperature At midday at 2000 m, between -5 °C in the northern regions and -1 °C in the southern regions. Wind

• Winds were blowing at light to moderate strength from westerly directions;
• moderate northerly winds were blowing in the southern regions during the afternoon.

Weather forecast through Sunday, 11.12.2022 In the northern regions and in Grisons, nocturnal skies on Saturday will be overcast and a small amount of snowfall is anticipated to fall down to low lying areas. During the daytime on Sunday in western and in southern regions, it will be quite sunny. In the eastern regions it will be partly sunny in the early part of the day. Fresh snow Between Saturday afternoon and the end of this period of precipitation, the following amounts of fresh snow are anticipated:

• central and eastern Prealps: 5 to 10 cm;
• in the remaining regions of Switzerland, only a few centimetres; in the Valais and the southern regions, it is expected to remain dry.

Temperature Cold at midday at 2000 m: -10 °C. Wind

• Winds will be blowing at light to moderate strength, at moderate to strong velocity in the central and eastern sectors of the Main Alpine Ridge, from northerly to easterly directions;
• on the southern flank of the Alps, strong-velocity northerly winds are anticipated, in some places extending down to the valleys.

Outlook through Tuesday, 13.12.2022 Monday In the northern regions skies will be overcast, accompanied by bright intervals. In the western regions it will be partly sunny, in the southern regions predominantly sunny. It is expected to remain cold.Avalanche danger levels will incrementally decrease. Tuesday In all likelihood there will still be a bit of sunshine only in the eastern regions tomorrow morning, in the other regions skies will be overcast. In the northern regions and in western regions, a small amount of snowfall is also likely, but the anticipated amounts are still quite uncertain.Depending on the amounts of precipitation, avalanche danger in the western regions and the northern regions could increase. In the eastern and the southern regions, avalanche danger levels will continue to decrease gradually.