Aigle-Leysin

The somewhat older wind slabs are in some cases still prone to triggering. The number and size of avalanche prone locations will increase with altitude. Avalanches can in some places be released by people and reach large size in isolated cases. Backcountry touring calls for meticulous route selection. Medium-sized and, in isolated cases, large wet avalanches are possible. This applies in particular on north facing slopes below approximately 2600 m, as well as on east, south and west facing slopes below approximately 3000 m. Backcountry tours and ascents to alpine cabins should be concluded timely.

The fresh fallen snow and freshly generated snowdrifts of this week are settling and consolidating to an increasing degree. Avalanche prone locations for dry-snow avalanches are found on north-facing slopes above approximately 2600 m more than anywhere else. On Thursday night the moist snowpack surface will freeze and form a crust which will be capable of bearing loads over widespread areas. During the course of the day on Friday the crust will soften, thaw and the entire snowpack will forfeit its stability. The old snowpack is thoroughly wet far up into high alpine regions on south-facing slopes, on west-facing and east-facing slopes it is wet below approximately 3000 m, and on north-facing slopes it is wet below approximately 2600 m.

On Wednesday night the nocturnal skies in the mountains were clear, only in the furthermost southern regions were skies partially overcast. During the daytime hours on Thursday it was sunny, in the southern regions increasingly so following the dispersal of cloudbanks during the morning. The zero-degree level ascended to approximately 3000 m from the west. Fresh snow: - Temperature: At midday at 2000 m, +6 °C in the western and the southern region and +4 °C in the eastern regions. Wind: Winds were blowing at light to moderate strength from northerly directions. Nighttime skies on Thursday night will be clear, in the furthermost southern regions nocturnal skies will be partially overcast. During the daytime hours on Friday it will be predominantly sunny, accompanied by cloudbanks in the furthermost southern regions. During the afternoon, high-altitude cloudbanks will move in from the northwest. The zero-degree level will lie at 3000 to 3200 m. Fresh snow: - Temperature: At midday at 2000 m, between +7 °C in the western regions and +5 °C in the southern regions. Wind: To start with, predominantly light winds will be blowing from northerly directions. Subsequently shifting to westerly and blowing at light to moderate strength in the northern regions during the course of the day.

Nocturnal skies on Friday night will be overcast. Precipitation is expected to set in. The snowfall level will descend from 2200 m down to 1500 to 1800 m. During the daytime hours on Saturday skies will be variably cloudy to heavily overcast with showers and also thunderstorms over widespread areas. The precipitation will come to an end during Saturday night. On Sunday, skies will be variably cloudy, accompanied by isolated showers and some bright intervals. In the western regions, it is expected to become increasingly sunny. At high altitudes on the northern Alpine Ridge, 20 cm of fresh snow is anticipated, less in the other regions of Switzerland. Winds will be blowing predominantly at moderate strength at high altitudes; on Saturday from westerly to northwesterly directions and on Sunday from easterly to northeasterly directions. The danger of dry-snow avalanches is expected to increase slightly from place to place in the northern regions more than anywhere else on Saturday, subsequently not change significantly on Sunday. The danger of wet-snow avalanches will decrease initially, then on Sunday presumably be subject to a slight daytime danger cycle in the western regions in particular.