Gruyère

As the day progresses a moderate danger of wet avalanches will be encountered over a wide area

As the day progresses a moderate danger of wet avalanches will be encountered over a wide area

Only a little snow is lying. The snowpack will be wet all the way through. Dry avalanches are no longer to be expected. Only a little snow is lying. The snowpack will be wet all the way through. On very steep slopes individual gliding avalanches and wet snow slides are possible. Caution is to be exercised in areas with glide cracks.

During the course of this last week, the snowpack swiftly became thoroughly wet to an increasing degree as a consequence of daytime warmth, overcast nocturnal skies and dust from the Sahara. The snowpack on south-facing slopes below 2500 to 2800 m, on east-facing and west-facing slopes below 2000 to 2300 m, is thoroughly wet. On north-facing slopes the process of becoming thoroughly wet has begun below 1700 to 2000 m. In the northern regions where snowfall has been heaviest, more than anywhere else, numerous glide cracks have opened in the snowpack surface. Gliding avalanches can become large-sized in some cases. In more deeply embedded layers inside the snowpack, particularly in the southern Valais as well as in the inneralpine and the southern regions, there are pronounced weak layers evident. Nevertheless, from the end of February until the middle of March, no fractures of dry-snow avalanches were recorded as triggering from these layers. Currently, as the moistening of the snowpack gets underway, fractures in these layers are again becoming possible, as first triggerings by persons have demonstrated.

Following unexpectedly strong outgoing longwave radiation during the nocturnal hours, during the daytime it was predominantly sunny in the eastern regions on Saturday, in the other regions of Swizterland rather sunny. In the furthermost western regions and in the central sector of the southern flank of the Alps, skies were overcast until the afternoon. Fresh snow: - Temperature: At midday at 2000 m, between +2 °C in the western regions and 0 °C in the eastern and the southern regions. Wind: Winds were easterly to southeasterly, - during the nighttime hours blowing at moderate to strong velocity in the western regions; - in the other regions of Switzerland, and during the daytime in all regions of Switzerland, blowing at light to moderate strength. Skies on Saturday night will be only partly clear, with varying amounts of cloud cover. On the Main Alpine Ridge and southwards therefrom, a small amount of snowfall is possible. During the daytime on Sunday it will be predominantly sunny in the eastern regions, rather sunny in the western regions. In the southern regions skies will be heavily overcast to start with, subsequently it will become partly sunny during the course of the day. Fresh snow: The snowfall level is expected to descend from 1200 down to 800 m. On Saturday night: - Main Alpine Ridge and southwards therefrom: 5 to 10 cm from region to region; - in the remaining regions of Switzerland it is expected to remain dry. Temperature: At midday at 2000 m, 0 °C in the northern regions and -5 °C in the southern regions. Wind: Winds will be southerly to southwesterly, - during the night temporarily strong; in the Alpine valleys of the north moderate-to-strong foehn; - during the daytime hours slackening off to a significant degree; during the afternoon blowing at light strength.

On Sunday night in the southern regions skies will be overcast. In the other regions of Switzerland skies will be clear, as they will also be on Monday night. During the daytime on both days, it will be predominantly sunny. Starting on Tuesday it will become somewhat warmer. The danger of dry-snow avalanches is not expected to change significantly. The danger of wet-snow and gliding avalanches will be subject to a daytime danger cycle typical of springtime, although gliding avalanches can also trigger during the nocturnal and early morning hours in isolated cases.