alto Moesano

In the south a high avalanche danger will persist in some regions.

Natural avalanches are further possible. They can be triggered in the old snowpack and reach large size, especially on north facing slopes above approximately 2400 m. The danger exists primarily in alpine snow sports terrain. Avalanches capable of reaching valley bottoms and endangering exposed transportation routes are unlikely to occur. Even single snow sport participants can release avalanches very easily. The conditions are very critical for backcountry touring.

Snowpack As the consequence of frequently intensive and persistent snowfall and moderate to strong-velocity southerly winds, far-reaching and trigger-sensitive snowdrift accumulations are being generated. Fresh fallen snow and freshly generated snowdrift accumulations on north-facing slopes above approximately 2600 m are being deposited on top of a loosely-packed old snowpack surface. Furthermore, on west-facing, north-facing and east-facing slopes above approximately 2200 m, there are weak layers evident deeply embedded inside the snow cover. Particularly in the major areas of precipitation on the Main Alpine Ridge and southwards therefrom, as well as in the inneralpine regions of the Valais and Grisons, fractures down to deeper layers inside the snowpack are possible. On the northern flank of the Alps and in northern Grisons, gliding avalanches are possible. Observed weather review Thursday, 20.04.2023 Nighttime skies in the inneralpine regions were partly clear, in the other regions of Switzerland skies were predominantly overcast. From region to region in the north there was some precipitation registered. During the daytime hours skies were overcast, accompanied by precipitation which intensified on the southern flank of the Alps during the course of the day. The snowfall level in the northern regions lay at approximately 1500 m, in the southern regions the snowfall level descended from 2000 down to 1600 m. Fresh snow Between Wednesday afternoon and Thursday midday the following amounts of fresh snow were registered:

• northern Lower Valais, central Ticino, Main Alpine Ridge from Lukmanier Pass as far as the Bernina above 2200 m: 10 to 30 cm;
• in the other regions of Switzerland, less; or else it remained dry.

Temperature At midday at 2000 m, over widespread areas -1 °C, in the Valais +2 °C. Wind Winds at high altitudes were blowing frequently at moderate strength, then shifting from northwesterly to southerly-to-southwesterly. Weather forecast through Friday, 21.04.2023 During the night, precipitation over wide-ranging areas is anticipated, both persistent and intensive on the central Main Alpine Ridge and southwards therefrom. During the daytime hours in the northern regions it will be intermittently sunny and predominantly dry, in the southern regions a small amount of additional precipitation is expected to fall until afternoon. The snowfall level in the northern regions will lie at approximately 1400 m, in the southern regions it will ascend from 1400 zo 1800 m. Fresh snow The following amounts of fresh snow are expected between Thursday midday and Friday afternoon above 2200 m:

• eastern Ticino, Moesano, Sotto Ceneri, Val Bregaglia, Bernina region: 50 to 70 cm;
• western Ticino, remaining parts of the Main Alpine Ridge from Lukmanier Pass as far as Bernina Pass: 30 to 50 cm;
• remaining parts of the Main Alpine Ridge from the Simplon region as far as Lukmanier Pass, central Grisons, regions Flims, Sarganserland and Calanda, as well as the remaining parts of Upper Engadine and Val Müstair: 15 to 30 cm;
• in the other regions of Switzerland, less than 15 cm.

Temperature At midday at 2000 m, between +4 °C on the northern flank of the Alps and 0 °C in the southern regions. Wind Winds will be blowing at moderate strength, at strong velocity in the high alpine regions, from southerly to southwesterly directions; in the Alpine valleys of the north, foehn wind is anticipated. Outlook through Sunday, 23.04.2023 On Saturday in the southern regions, skies will be overcast, in the other regions of Switzerland it will be partly sunny to begin with. During the afternoon, dense cloud cover will move in, but it is expected to remain dry. The zero-degree level will ascend to 2600 to 2800 m. On Sunday skies will be predominantly overcast, a small amount of intermittent snowfall is expected above 1500 to 2000 m. The danger of dry-snow avalanches will decrease. On Saturday as a result of higher daytime temperatures and solar radiation, numerous wet-snow avalanches can be expected, particularly in the areas where recent snowfall has been heaviest.