Waadtländer Voralpen

As a consequence of new snow and stormy weather a high avalanche danger will be encountered in some regions

As a consequence of new snow and stormy weather a high avalanche danger will be encountered in some regions

As a consequence of new snow and a storm force northwesterly wind, sometimes large wind slabs formed. The new snow and wind slabs are prone to triggering. Even single snow sport participants can release avalanches. In addition natural avalanches are possible. Avalanches can in isolated cases release deeper layers of the snowpack and reach large size. Backcountry touring and other off-piste activities call for extensive experience in the assessment of avalanche danger and restraint.

On Sunday night, a wintery storm will set in, bringing heavy precipitation. The storm is expected to transport the fresh fallen snow and old snow intensively. In zones distant from ridgelines, deep snowdrift accumulations will be generated in places. More deeply embedded inside the snowpack, particularly on west-facing, north-facing and east-facing slopes, pronounced weak layers are evident. On the northern flank of the Alps, these weak layers are generally blanketed over by thick layers.From the southern Valais over the northern Ticino as far as Grisons, the entire old snowpack is expansively metamorphosed in numerous areas. The old snowpack, particularly in the inneralpine regions, is prone to triggering. On the weekend, numerous large-sized avalanches were triggered by persons in those regions, in isolated cases the releases were very-large sized.

In the Jura region skies were predominantly overcast, but it remained largely dry until afternoon. In the other regions of Switzerland it was initially quite sunny, accompanied by cloudbanks, but skies become increasingly overcast from the northwest during the course of the day. Fresh snow: - Temperature: At midday at 2000 m, between -3 °C in the northern regions and -1 °C in the southern regions. Wind: Winds were westerly to southwesterly, - on Saturday night and during the daytime on Sunday, also in the Ticino and in Grisons, blowing at light to moderate strength; - intensifying in the course of the day, as well as in the western and the northern regions blowing at moderate to strong velocity. On Sunday night, heavy precipitation is expected to set in. Accompanied by storm-strength westerly to northwesterly winds, the precipitation will extend far into the southern regions. Only in Sotto Ceneri will it remain dry. Initially the snowfall level will ascend for a brief spell from 800 m to approximately 1400 m. Subsequently during the course of the night, the snowfall level will again descend to approximately 600 m. During the daytime on Monday, skies will be heavily overcast to begin with, the snowfall will slacken off from the west. In the western and the southern regions it will be partly sunny in the afternoon. Fresh snow: Between Sunday afternoon and Monday afternoon, the following amounts of fresh snow are anticipated above 1600 m: - northern Alpine Ridge, Valais not including Saastal and also not including the southern Simplon region, northern Grisons, Silvretta, Samnaun: 30 to 50 cm; - Jura region, remaining regions of the northern flank of the Alps, Saastal, southern Simplon region, and the remaining parts of the Gotthard region, central Grisons, remaining parts of Lower Engadine: 20 to 40 cm; - further to the south: 5 to 20 cm; in the Sotto Ceneri it will remain dry. Due to storm-strength winds the fresh fallen snow will be distributed and deposited in highly irregular fashion. Temperature: Temperatures will drop. At midday at 2000 m: -9 °C in the northern regions and -6 °C in the southern regions. Wind: - Winds will be blowing from westerly to southwesterly directions to start with, subsequently on Sunday night shifting to northwesterly and blowing at strong to storm-strength. Strong storm winds will be blowing in high alpine regions. - In the southern regions, strong to storm-strength northerly winds extending down to low lying areas.

Tuesday: In the early morning hours in the eastern regions, skies will initially still be overcast. In the other regions of Switzerland it will be predominantly sunny. In the mountains a strong-velocity northerly wind will still be blowing, slackening off during the course of the day. Temperatures are expected to rise significantly from the west. The danger of naturally triggered dry-snow avalanches will decrease. For winter sports enthusiasts venturing into outlying terrain away from secured ski pistes the situation is extremely critical from region to region. As a result of solar radiation and daytime warming, the danger of wet-snow and gliding avalnches will increase. Wednesday: It will be sunny and, in the mountains, very mild. The zero-degree level will ascend to nearly 3500 m. The danger of dry-snow avalanches will decrease, however on shady slopes only incrementally. Particularly in the inneralpine regions, the avalanche situation in outlying terrain remains critical. As a consequence of solar radiation and daytime warming, the danger of wet-snow and gliding avalanches will increase.