Waadtländer Voralpen

As a consequence of new snow and wind a considerable avalanche danger will be encountered over a wide area

As a consequence of new snow and wind a considerable avalanche danger will be encountered over a wide area

As a consequence of new snow and a strong southwesterly wind, further wind slabs will form especially adjacent to ridgelines. These can be released by a single winter sport participant. Mostly avalanches are small. The wind slabs are to be avoided especially in very steep terrain. On very steep grassy slopes gliding avalanches and moist snow slides are to be expected.

As a result of strong-velocity westerly winds the loosely-packed snow is being transported in many places. Particularly in the regions on the northern flank of the Alps where recent snowfall has been heaviest, large-sized snowdrift accumulations are forming which are prone to triggering. Prior to the snowfall of the last four days there was little snow on the ground in the western and the northern regions. In the Jura region and the Prealps the fresh snow fell predominantly on bare ground. Where there was already snow, the bonding of the fresh snow/freshly generated drifts with the old snowpack beneath it in many places, particularly on west-facing, north-facing and east-facing slopes above approximately 2000, is unfavourable. Avalanches can be triggered at this transition point between snow layers. As a result of higher temperatures below 2000 m, gliding avalanches can be expected on the northern flank of the Alps more than anywhere else. These releases can grow to medium size.

During the night the snowfall came to an end in the northern regions. During the daytime in the northern regions skies were predominantly overcast. On the northern flank of the Alps and in Grisons, snowfall set in once again during the course of the morning. The snowfall level lay in low lying areas. On the southern flank of the Alps it was quite sunny and dry. Fresh snow: During the night in the central and eastern sectors of the northern flank of the Alps as well as in the northern Prättigau, an additional amount of snowfall was registered (up to 15 cm). In the remaining regions of Switzerland there was only a small amount of additional snowfall or else it remained dry. Thus, between Friday evening and Tuesday morning the following overall amounts of fresh snow were registered: - Northern flank of the Alps from Lake Brienzersee as far as the Säntis: 60 to 90 cm, more than 100 cm in some places in the Glarus Alps; - remaining sectors of the northern flank of the Alps, Emosson, remaining parts of the Gotthard region, northern Grisons, Moesano and eastern Ticino: 30 to 60 cm; - in the other regions of Switzerland, 15 to 30 cm. Temperature: At midday at 2000 m, between -7 °C in the northern regions and -3 °C in the southern regions. Wind: Winds were frequently blowing at strong velocity, from northerly to northwesterly directions during the night, during the daytime shifting to westerly. In the evening and during the early part of the night in the northern regions, snowfall is anticipated over widespread areas, subsequently skies will clear up. The snowfall level will lie at approximately 1000 m. In the southern regions skies will be clear. During the morning hours, cloud cover will move in from the northwest. Subsequently in the Jura region, in the western sector of the northern flank of the Alps and in the Valais, a small amount of precipitation is anticipated. The snowfall level in the Jura region and on the northern flank of the Alps will lie at approximately 1300 m, in the Valais in low lying areas. In the eastern and southern regions, skies will be overcast also during the afternoon, but it is expected to remain dry. Fresh snow: Between Tuesday midday and Wednesday afternoon, the following amounts of fresh snow are expected above 1500 m: - Northern Alpine Ridge from the Aletsch region into the Alpstein, as well as Silvretta and Samnaun: 10 to 20 cm; in the Urner and Glarus Alps, as well as in the Samnaun, as much as 30 cm; - in the other regions of Switzerland, only a few centimetres; on the southern flank of the Alps it is expected to remain dry. Temperature: At midday at 2000 m, between 0 °C in the northern regions and -4 °C in the southern regions. Wind: Jura region, Prealps, as well as generally at high altitudes: winds will be blowing at moderate to strong velocity, frequently intensifying to storm strength during the afternoon, from southwesterly to westerly directions.

On Thursday and on Thursday night in the northern regions, snowfall is anticipated. On the northern flank of the Alps, in the Lower Valais, as well as in northern Grisons, 20 to 40 cm of fresh snow is expected over widespread areas. The snowfall level will descend once again down to low lying areas. On Friday it will remain predominantly dry. On Thursday in the southern regions, skies will be overcast, accompanied by a small amount of precipitation; on Friday it will be predominantly sunny as a result of increasingly strong northerly winds. Avalanche danger levels are expected to increase over widespread areas in the northern regions as a result of fresh fallen snow and wind. In the southern regions, avalanche danger is not expected to change significantly.