Waadtländer Voralpen

The snowpack is moist. As a consequence of warming during the day individual wet snow slides are possible as the day progresses. This applies in particular on very steep north facing slopes. Restraint should be exercised because avalanches can sweep people along and give rise to falls.

The fresh fallen snow was deposited on top of a generally moist snowpack surface. Only on steep north-facing slopes above approximately 2600 m was the snowpack surface dry and still loosely-packed in some places. There, more than anywhere else, weak bonding of the fresh fallen snow to the old snowpack can be expected. In the three days prior to this period of precipitation, slab avalanches were triggered by persons above 3000 m in the near-surface dry-snow layers of the snowpack predominantly on north-facing slopes. Triggerings in these somewhat more deeply embedded layers of the snowpack are presumably only possible in isolated cases. The old snowpack is thoroughly wet on south-facing slopes far up into high alpine regions, on west-facing and east-facing slopes it is wet below approximately 3000 m, and on north-facing slopes below approximately 2600 m.

On Friday night, precipitation set in from the west. The precipitation persisted into the daytime hours and subsequently turned increasingly shower-like. In the western sector of the northern flank of the Alps and in the Valais there were some bright intervals, in the other regions of Switzerland skies remained gray. Fresh snow: The snowfall level lay between 1800 and 2000 m for the most part. At high altitudes, the following amounts of fresh snow were registered:

• Temperature: At midday at 2000 m, between +4 °C in the western regions and +1 °C in the remaining regions of Switzerland. Wind: Winds were blowing from northerly directions,

Monday: Skies on Sunday night will be predominantly clear in the western and the northern regions, in the southern and eastern region only partly clear. During the morning hours on Monday it will be quite sunny, subsequently increasingly overcast during the course of the day, accompanied by showers. The zero-degree level will climb to 2600 m. Winds will be light. The danger of dry-snow avalanches is expected to decrease. The danger of wet-snow avalanches will increase during the course of the day. In the eastern regions more than anywhere else, numerous slides can be expected to trigger from the fresh snow. Tuesday: Nocturnal skies on Monday night will be predominantly overcast and the outgoing longwave radiation will be inadequate. During the daytime hours on Tuesday, skies will be variably cloudy accompanied by bright intervals and showers during the afternoon in particular. The danger of dry-snow avalanches will decrease. Isolated wet-snow avalanches are possible at any time of day.