Génépi

Considerable avalanche danger will be encountered over a wide area.

The new snow and wind slabs of the last few days are lying on the unfavourable surface of an old snowpack. Single winter sport participants can release avalanches. Avalanches can also penetrate near-ground layers of the snowpack and reach large size in isolated cases. These avalanche prone locations are to be found in particular on north facing slopes above approximately 2400 m and on south facing slopes above approximately 2800 m. Whumpfing sounds and the formation of shooting cracks when stepping on the snowpack can indicate the danger. Backcountry touring and other off-piste activities call for experience in the assessment of avalanche danger.

Snowpack The fresh fallen snow from the beginning of the week in western and northern regions is settling and stabilising to an increasing degree. Still fresher surface-near snowdrift accumulations are prone to triggering in some places. More deeply embedded expansively metamorphosed (faceted) and loosely-packed layers are evident inside the old snowpack. These layers are prone to triggering, particularly in the region extending from southern Valais over the Gotthard regions as far as Grisons. In the remaining regions of Switzerland these weak layers occur more seldom or else they are no longer likely to trigger. These weak layers which are deeply embedded inside the snowpack are to be found on north-facing slopes above 2200 to 2400 m and on south-facing slopes above approximately 2800 m. Observed weather review Wednesday, 11.01.2023 Following a night of partly clear skies, cloud cover swiftly moved in from the northwest during the morning hours. Snowfall set in to begin with in the Jura region, later on also on the northern flank of the Alps and in the Valais. The snowfall level lay at 1800 m to start with. Fresh snow On the highest summits of the western Jura region, on the northern flank of the Alps and in the Lower Valais, only a few centimetres. Temperature At midday at 2000 m, +1 °C. Wind During the nocturnal hours, winds were blowing at light to moderate strength, during the daytime hours in northern regions intensifying from moderate to strong velocity, from southwesterly directions. Weather forecast through Thursday, 12.01.2023 In the early part of the night, a small amount of snowfall is anticipated in the northern regions. The snowfall level is expected to descend to 1000 m. During the daytime hours, skies will be heavily overcast in the northern regions. In the southern regions it will be quite sunny. Fresh snow Between Wednesday afternoon until the nighttime hours on Wednesday:

• northern flank of the Alps, furthermost western part of Lower Valais: 10 to 20 cm;
• in the other regions of Switzerland, only a few centimetres over widespread areas; on the southern flank of the Alps it will remain predominantly dry.

Temperature At midday at 2000 m, -2 °C. Wind

• in the northern regions and in general at high altitudes, strong velocity winds from westerly to northwesterly directions;
• in the southern regions, temporarily strong velocity northerly winds during the nocturnal hours;
• in the remaining regions of Switzerland, predominantly moderate-strength winds.

Outlook through Saturday, 14.01.2023 On Friday in the northern and the western regions a bit of snowfall is anticipated above approximately 1200 m. The westerly winds will be blowing at strong velocity to storm strength. On Saturday in the northern regions, skies will be heavily overcast for the most part. Presumably, only a small amount of snowfall will be deposited above approximately 1400 m. The winds will slacken off somewhat. In the southern regions it will be quite sunny on both days. Avalanche danger levels are not expected to change significantly on Friday; on Saturday they will decrease somewhat.