Bex-Villars

Significant increase in avalanche danger in the west.

Large quantities of fresh snow and the wind-drifted snow are lying on top of a weakly bonded old snowpack. Single winter sport participants can release avalanches easily, including large ones. Avalanches can in some cases release the entire snowpack. An increasing number of natural avalanches are to be expected. In the afternoon danger level 4 (high) will be reached. The danger exists primarily in alpine snow sports terrain. Backcountry touring calls for extensive experience in the assessment of avalanche danger and restraint.

Snowpack As a consequence of fresh fallen snow and strong-velocity winds, far-reaching snowdrift accumulations are being generated in the western regions more than anywhere else. Fresh fallen snow and freshly generated snowdrift accumulations lie deposited on top of an unfavourable weak snow cover which is extraordinarly shallow for this juncture of the season. The old snowpack below 2200 to 2400 m manifests pronounced effects of higher temperatures and rainfall and, as a result of melt-freeze crusts, is also riddled with expansively metamorphosed (faceted) layers. At elevated altitudes the more deeply embedded layers inside the snowpack are frequently faceted and loosely-packed. This is the case on west-facing, north-facing and east-facing slopes above 2200 to 2400 m and on south-facing slopes above approximately 2700 m. In these zones, avalanches can fracture also inside the weak layers of the old snowpack and subsequently sweep away the entire snow cover. Below approximately 1700 m the fresh snow will in many regions be deposited on bare ground. Observed weather review Sunday, 08.01.2023 During the nocturnal hours in the western and the southern regions, precipitation set in. During the daytime hours skies were heavily overcast and there was a small amount of precipitation over widespread areas. The snowfall level lay between 1000 and 1400 m. Fresh snow By Sunday afternoon, above approximately 1600 m:

• Lower Valais: 10 to 15 cm;
• central sector of the southern flank of the Alps, regions from Val Bregaglia as far as the Bernina: 5 to 10 cm;
• in the remaining regions of Switzerland, only a few centimetres.

Temperature At midday at 2000 m, approximateely -2 °C. Wind Winds were blowing at moderate to strong velocity from southwesterly directions. Weather forecast through Monday, 09.01.2023 Skies are expected to be predominantly overcast over widespread areas and precipitation is anticipated over far-reaching zones. The snowfall level will descend during the nighttime hours from approximately 1400 m down to low lying areas. As a result of the northwesterly winds which will arise, the zones on the southern flank of the Alps will be predominantly dry over the daytime and, particularly in the morning hours, partly sunny. Fresh snow Above approximately 1600 m:

• Chablais, Vaud Alps, northern and furthermost western Lower Valais: 30 to 50 cm; in the furthermost western regions up to 60 cm from place to place;
• western Jura region, Fribourg Alps, western part of Bernese Oberland, northern Alpine Ridge from the Wildstrubel as far as the Reuss, remaining parts of Lower Valais, from Val Bregaglia into Val Poschiavo: 20 to 30 cm;
• in the other regions of Switzerland, 10 to 20 cm over widespread areas.

Temperature Temperatures are expected to drop. At midday at 2000 m to between -6 °C in the northern regions and -4 °C in the southern regions. Wind Winds will be blowing at strong velocity, in some high altitude regions at storm strength; during the nocturnal hours from the southwest, shifting from westerly to northwesterly directions during the daytime hours. Outlook through Wednesday, 11.01.2023 Tuesday On Monday night and during the morning hours on Tuesday in the northern regions, more snowfall is expected to fall down to low lying areas. The major thrust of the snowfall will extend into the regions from the eastern part of the Bernese Oberland into the Glarus Alps and to northern Grisons, where an additional 20 to 40 cm of fresh fallen snow is anticipated. During the daytime hours, the precipitation will slacken off and some bright intervals are expected. Winds will be blowing at strong velocity from northwesterly directions. In the furthermost southern regions it will remain dry, amid strong to storm-strength northerly winds, and quite sunny. The avalanche danger levels are expected to increase another notch. In the Lower Valais and on the northern Alpine Ridge, Danger Level 4 (high) will be reached. As a result of the shallow snowpack at low and intermediate altitudes, it is mainly the alpine snow-sports terrain which will be affected. Wednesday On Tuesday night a small amount of precipitation is anticipated, the snowfall level will rapidly ascend from the west up to nearly 1800 m. During the course of the day on Wednesday the precipitation will intensify once again and the snowfall level descend by evening to nearly 1200 m. In the furthermost western part of Lower Valais and on the northern flank of the Alps, an additional 15 to 30 cm of fresh snow is expected at high altitudes on Wednesday. Winds will be blowing at strong velocity from westerly directions. In the furthermost southern regions it will remain dry and there will be some bright intervals. The avalanche danger situation will continue to remain very critical.