Luganese

A very critical avalanche situation will be encountered in some regions

A very critical avalanche situation will be encountered in some regions

Thus far only a little snow is lying. The fresh wind slabs are mostly small but in some cases prone to triggering. They are to be evaluated with care and prudence in very steep terrain. Apart from the danger of being buried, restraint should be exercised as well in view of the danger of avalanches sweeping people along and giving rise to falls.

In the lowermost part of the snowpack in nearly all regions on west-facing, north-facing and east-facing slopes above approximately 2200 m there are layers with expansively metamorphosed (faceted) crystals. Avalanches can easily be triggered in these layers from central Valais as far as Grisons as well as in general in places where the snow is shallow. In the western Lower Valais and on the northern flank of the Alps, the weak old snow is frequently overlain with thick layers and thus, less prone to triggering. The fresh fallen snow and freshly generated snowdrifts from Wednesday are prone to triggering in many places. On Thursday the fresh snow and loosely-packed surface-near snow will be transported by northerly winds in the central sector of the Main Alpine Ridge more than anywhere else, and additional snowdrift accumulations will be generated.

On Tuesday night, precipitation set in from the west. The snowfall level during the night lay temporarily at 1200 m, subsequently descended down to low lying areas. During the daytime there was snowfall registered over widespread areas, in some places the snowfall was heavy. Fresh snow: Fresh snow between Tuesday evening and Wednesday afternoon: - western and central sectors of the northern flank of the Alps, as well as Lower Valais and the Jura region: 20 to 30 cm, as much as 40 cm in the furthermost western regions; - eastern sector of the northern flank of the Alps, Upper Valais, central Grisons as well as the southern flank of the Alps: 10 to 20 cm; - in the other regions of Switzerland, only a few centimetres. Temperature: - At midday at 2000 m, between -6 °C in the western regions and -4 °C in the eastern regions. Wind: - Winds in the northern regions were blowing at moderate to strong velocity from the southwest during the nocturnal hours, with foehn wind blowing in the northern Alpine valleys. During the daytime, light to moderate winds from westerly directions were blowing; - winds were blowing at light to moderate strength in the southern regions. The snowfall is expected to persist through Thursday night. During the course of the morning on Thursday the precipitation will come to an end in the southern regions and in the west. Isolated bright intervals are possible in those regions during the afternoon. In the eastern sector of the northern flank of the Alps and in Grisons the snowfall will continue until afternoon. Fresh snow: Fresh snow between Wednesday and Thursday afternoon: - northern flank of the Alps from the Wildstrubel as far as Alpstein and northern Grisons: 20 to 40 cm; - remaining parts of the northern flank of the Alps, Valais and the remaining parts of Grisons: 15 to 30 cm over widespread areas; - in the other regions, only a few centimetres. Temperature: - At midday at 2000 m, between -10 °C in the northern regions and -6 °C in the southern regions. Wind: - Winds in the northern regions will be blowing at moderate to strong velocity from northwesterly directions; - in the central and eastern sectors of the Main Alpine ridge and southwards therefrom, blowing at strong velocity from northerly directions.

Friday: On Friday, weather conditions will be variable, skies could be heavily overcast. During the course of the morning hours, snowfall will set in once again from the west. The snowfall level will lie at approximately 600 m. Winds in the northern regions will be blowing at moderate to strong velocity from southwesterly directions. In the southern regions winds will be light. Avalanche danger levels are not expected to change significantly. Saturday: On Friday night the precipitation will come to an end. In the northern regions conditions will be variably cloudy to heavily overcast skies. In the southern regions it will be quite sunny. Winds will be blowing from northerly directions: in the southern regions at strong velocity, intermittently at storm-strength; in the northern regions at moderate to strong velocity. In the central sector of the Main Alpine Ridge and southwards therefrom, additional snowdrift accumulations are expected to form, and avalanche danger levels will increase somewhat. In the northern regions, avalanche danger is not expected to change significantly.