Waadtländer Voralpen

Considerable avalanche danger will be encountered over a wide area

Considerable avalanche danger will be encountered over a wide area

As a consequence of new snow and wind the wind slabs will increase in size additionally. Natural avalanches are possible. Avalanches can be released by a single winter sport participant and reach large size in isolated cases. Experience in the assessment of avalanche danger is required.

As a result of fresh snow and strong-velocity winds, the snowdrift accumulations generated over the last few days, particularly in the western and the northern regions, continue to grow. Beneath the fresh snow and freshly generated snowdrifts of this week, the old snowpack surface is very hard and in many regions showed striking effects of rain, wind and sun. In the inneralpine regions of the Valais and Grisons in particular, the crust was less pronounced and frequently breakable. From the central Valais over the northern Ticino as far as Grisons more than anywhere else, avalanches can in very isolated cases be triggered in the old snow at high altitude. This danger applies to expansively metamorphosed (faceted) loose-snow layers either immediate beneath the rain crust which formed at the end of December or more deeply embedded inside the snowpack.

In the northern regons skies were predominantly overcast during the morning hours. Intermittent snowfall was registered down to low lying areas. During the afternoon there were bright intervals, particularly in Grisons. In the southern regions it was quite sunny during the daytime. Fresh snow: Between Friday afternoon and Saturday afternoon: - furthermost western part of Lower Valais, northern Alpine Ridge, Jura region: 10 to 20 cm; - in the other regions of Switzerland, less; in the Ticino and the Engadine it remained dry Temperature: At midday at 2000 m, -9 °C in the northern regions and -6 °C in the southern regions. Wind: Winds on the northern flank of the Alps were blowing at strong velocity in some places, otherwise at moderate strength, from westerly to northwesterly directions. Skies will be overcast and snowfall is expected to fall down to low lying areas. In the furthermost southern regions it will remain predominantly dry and partly sunny. Fresh snow: The following amounts of fresh snow are expected between Saturday afternoon and Sunday afternoon: - furthermost western part of Lower Valais: 30 to 50 cm; - Vaud Alps, northern Lower Valais, western Jura region: 20 to 40 cm; - remaining parts of the northern flank of the Alps, remaining parts of Valais, Grisons north of Anterior Rhine and the eastern Jura region: 15 to 30 cm; - remaining regions of Switzerland: 5 to 15 cm; in the furthermost southern regions less, or else it will remain dry. Temperature: At midday at 2000 m, -9 °C. Wind: During the nocturnal hours, a strong to storm-strength southeasterly wind will be blowing. During the daytime, winds will shift to northerly and be blowing at strong velocity in southern regions, in the other regions of Switzerland at moderate strength, at high altitudes.

On Sunday night a small amount of snowfall is expected. During the daytime on Monday it will become increasingly sunny in the western regions. In the eastern regions skies will remain predominantly overcast. In the southern regions it will be dry and mostly sunny. On Tuesday it will be sunny and, in the western and the southern regions, milder. On both days, a moderate to strong-velocity northeasterly wind will be blowing in the southern regions and in general at high altitudes. In the northern regions, avalanche danger will decrease. In the southern regions avalanche danger levels are not expected to change significantly.