Bex-Villars

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

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

The new snow and wind slabs are in some cases prone to triggering at elevated altitudes. The number and size of avalanche prone locations will increase as the day progresses. By the middle of the day danger level 3 (considerable) will be reached. Single snow sport participants can release avalanches. In many cases they are medium-sized. Backcountry touring and other off-piste activities call for experience in the assessment of avalanche danger. Over a wide area new snow is lying on a wet old snowpack. In particular below approximately 2200 m moist snow slides are possible.

After a lengthy period of dryness, a several-day period of snowfall began on Wednesday, with minor snowfall to start with. The fresh snow blankets a rawly configured old snowpack surface in many places and is generally well bonded with it. As Friday approaches, the snowfall will intensify and fresh snowdrift accumulations will be generated in high altitude terrain more than anywhere else. The old snowpack on north-facing slopes below approximately 1800 m, on east-facing slopes below approximately 2500 m, on south-facing slopes up to over 3000 m, and on west-facing slopes below approximately 2800 m, is thoroughly wet. As a consequence of the decreasing temperatures, hardly any wet-snow and gliding avalanches are to be expected. Prior to the current snowfall in the northern regions on north-facing slopes above approximately 1000 to 1400 m, in southern regions above approximately 1800 to 2200 m, there was a cohesive, area-wide snowpack. On south-facing slopes the snowline lay generally 300 to 500 m higher up. Over widespread areas there is significantly less snow on the ground than is normal for this juncture of the season, in the southern regions there is extraordinarly less snow on the ground. As a result of the thin, often expansively metamorphosed (faceted) snowpack there continues to be heightened danger of falling into crevices on the glaciers, most particularly in the southern Valais.

In the northern regions skies were heavily overcast, accompanied by some bright intervals in Central Switzerland in particular. In the southern regions it was partly sunny. There was some precipitation in the form of showers, most of them in the western regions. The snowfall level lay at 1400 to 1700 m. Fresh snow: Between Wednesday morning and Thursday afternoon above approximately 1800 m, the following amounts of fresh snow were registered: - Lower Valais, Vaud and Fribourg Alps: approximately 10 cm; - in the remaining regions of Switzerland, only a few centimetres from place to place. Temperature: At midday at 2000 m, between -2 °C in the northern regions and +2 °C in the southern regions. Wind: Winds during the nocturnal hours were light, during the daytime hours blowing at light to moderate strength, from westerly to northerly directions. Skies are expected to be heavily overcast; in the southern regions, short bright intervals are possible. The precipitation will intensify on Thursday evening and persist during the daytime on Friday in the northern regions in particular. The snowfall level will descend on Thursday night to approximately 1000 m, then during the course of the day on Friday down to low lying areas. Fresh snow: Between Thursday afternoon and Friday afternoon above approximately 1500 m: - Northern Alpine Ridge: 30 to 40 cm; - remaining regions of the northern flank of the Alps, of Lower Valais and of Grisons: 15 to 30 cm; - in the other regions of Switzerland: 10 to 20 cm; in the Ticino, less. Temperature: Temperatures are expected to drop. At midday at 2000 m: in the northern regions -5 °C and in the southern regions -1 °C. Wind: Winds in the mountains will be blowing predominantly at moderate strength from northerly to easterly directions, at 4000 m altitude from southerly to southeasterly directions.

Skies will be predominantly overcast, accompanied by snowfall extending down to low lying areas. In the areas south of the Main Alpine Ridge only a small amount of precipitation is anticipated, and it will be sunny for the most part. Between Friday afternoon and Sunday afternoon in the Lower Valais, on the northern flank of the Alps and in northern Grisons, an additional 15 to 30 cm of fresh snow is anticipated, as much as 40 cm from place to place on the northern flank of the Alps is possible. Winds will be blowing at moderate strength, intermittently at strong velocity, from northeasterly directions. Avalanche danger levels are expected to further increase in the major areas of precipitation on Saturday, in the other regions of Switzerland avalanche danger is not expected to change significantly. Avalanches are triggerable particularly inside the layers of fresh fallen snow and freshly generated snowdrift accumulations from this week.