Pays d'Enhaut

As a consequence of new snow and warming a considerable avalanche danger will be encountered in some regions.

The fresh wind slabs are prone to triggering. Single winter sport participants can release avalanches, including medium-sized ones. Avalanches can in isolated cases penetrate deep layers and reach large size. This applies in particular above approximately 2400 m. Backcountry touring and other off-piste activities call for experience in the assessment of avalanche danger.

As a consequence of warming small to medium-sized wet and gliding avalanches are to be expected below approximately 2400 m.

Snowpack At altitudes below approximately 2200 m there is extraordinarily little snow on the ground for this juncture of the season, at low altitudes in flat fields where measurements are recorded no snow at all. Even above 2200 m the snow depths are below average over widespread areas. Only in the Valais do snow depths correspond to long-term averages. The generally thin snow cover below 2200 to 2400 m shows pronounced effects from the higher temperatures and rainfall. It is riddled with melt-freeze crusts, but also with expansively metamorphosed (faceted) crystal layers. At elevated altitudes the more deeply embedded layers are generally expansively metamorphosed (faceted) and loose. This applies to west-facing, north-facing and east-facing slopes above 2200 to 2400 m and to south-facing slopes above approximately 2700 m. On Friday afternoon in the western and the northern regions, southwesterly winds intensified and transported the fresh fallen snow and the loose old snow. The snowdrift accumulations will continue to grow in both size and spread on Friday night. Fresh fallen snow and freshly generated snowdrifts are prone to triggering, particularly on wind-protected shady slopes. As a consequence of the rainfall, the snowpack below approximately 2200 m will be weakened and moist slides and gliding avalanches can be expected. Observed weather review Friday, 30.12.2022 On Thursday night in the western regions and the Prealps more than anywhere else, there was precipitation registered. The snowfall level descended to approximately 1200 m. During the daytime hours on Friday it was temporarily dry and, in the eastern regions, partly sunny. Starting at midday, precipitation set in from the west. The snowfall level ascended swiftly in the northwestern regions to approximately 2200 m. In the remaining regions of Switzerland the snowfall level ascended to approximately 1500 m. Fresh snow Between Thursday evening and Friday afternoon, the following amounts of fresh snow were registered above approximately 2200 m:

• northern Lower Valais, Vaud Alps: 20 to 30 cm;
• western sector of the northern flank of the Alps, southern part of Lower Valais: 10 to 20 cm;
• in the other regions of Switzerland, less; or else it remained dry.

Temperature At midday at 2000 m, between +2 °C in the northern regions and -2 °C in the southern regions. Wind Winds were southwesterly:

• blowing at light to moderate strength on Thursday night;
• intensifying during the course of the day on Friday, starting at midday in the western regions blowing at strong velocity, otherwise at moderate strength at elevated altitudes;
• in the upper foehn-impacted valleys of the north during the course of the day, moderate to strong-velocity southerly winds.

Weather forecast through Saturday, 31.12.2022 On Friday night skies will be predominantly overcast and in the western and the northern regions precipitation is anticipated, falling as snow above 2300 m. The precipitation will come to an end in the latter part of the night. During the daytime hours on Saturday it will be predominantly sunny, in the eastern regions the residual clouds will disperse in early morning. In the mountains it is expected to be extremely mild, the zero-degree level will ascend to 3200 m during the course of the day. Fresh snow Between Friday evening and Saturday morning the following amounts of fresh snow are expected above 2500 m:

• furthermost western part of Lower Valais: 10 to 20 cm;
• remaining parts of Lower Valais, remaining parts of northern Alpine Ridge, northern Prättigau: 5 to 10 cm;
• in the remaining regions of Switzerland, less; or else it will remain dry.

Temperature Temperatures are expected to rise: at midday at 2000 m to +8 °C in the northern regions and to +3 °C in the southern regions. Wind Winds will be southwesterly:

• in the northern regions blowing at moderate to strong velocity, at elevated altitudes even attaining storm strength;
• in the southern regions blowing at light to moderate strength, at high altitudes at moderate strength;
• in the foehn-impacted zones of the north, a moderate to strong-velocity southerly wind will be blowing.

Outlook through Monday, 02.01.2023 In the northern regions skies will be predominantly sunny accompanied by cloudbanks. On Monday afternoon heavy cloud cover will move in from the west. In the central sector of the southern flank of the Alps skies will be predominantly overcast on both days and a small amount of precipitation is expected from place to place, falling as snow above 1500 to 1800 m. In the northern regions it will remain very mild. The southwesterly winds will continue to blow at strong velocity, intermittently even reaching storm strength. The danger of dry-snow avalanches is not expected to change significantly at high altitudes. During the course of each day, moist slides and gliding avalanches are possible on steep sunny slopes.