Pays d'Enhaut

At elevated altitudes a considerable avalanche danger will be encountered over a wide area

At elevated altitudes a considerable avalanche danger will be encountered over a wide area

In particular at elevated altitudes sometimes large wind slabs formed. These can be released easily in some places, especially at their margins. Single winter sport participants can release avalanches, including dangerously large ones. Avalanches can additionally in isolated cases be released in the weakly bonded old snow on little-used, rather lightly snow-covered shady slopes. This applies in particular above approximately 2000 m in the western part of the northern flank of the Alps. Backcountry touring and other off-piste activities call for experience in the assessment of avalanche danger and careful route selection. The weather will be very mild. As a consequence of warming during the day and solar radiation more wet and gliding avalanches are possible. To some extent wet avalanches can also release deeper layers of the snowpack and reach large size in isolated cases. Caution is to be exercised on very steep sunny slopes below approximately 2800 m, as well as on shady slopes below approximately 2200 m.

The snowpack has been moistened, as a consequence of rainfall, from the Valais over the northern flank of the Alps as far as northern and central Grisons up to altitudes of approximately 2000 to 2200 m. At lower altitdues and in places where the snow is shallow, the snowpack is thoroughly wet in some places. Wet-snow and gliding avalanches have been observed in particular on the northern flank of the Alps and in the Lower Valais; in the western regions these releases fractured to more deeply embedded layers of the snowpack and in isolated cases grew to large size. With the termination of the rainfall, activity of wet-snow avalanches is expected to decrease. At high altitudes, deep snowdrift accumulations were generated in some places as a result of the westerly winds. To start with, these snowdrift accumulations are still prone to triggering. The persistent weak layer which prevails from the southern Valais over the northern Ticino as far as Grisons still needs to be evaluated with great caution due to the current higher temperatures and precipitation. Avalanches can trigger in deeper down layers inside the snowpack particularly on less-frequented west-facing, north-facing and east-facing slopes. In isolated cases avalanches can also grow to large size.

In the western and the southern regions skies were predominantly overcast and there was intermittent precipitation registered. The snowfall level lay at 1800 to 2200 m over widespread areas. In the Ticino and in southern Grisons, it was partly sunny and generally dry. Fresh snow: Between Wednesday afternoon and Thursday afternoon, the following amounts of fresh snow were registered above approximately 2200 m: - western sector of the northern flank of the Alps, northern Valais: 15 to 30 cm; - Glarus Alps, Alpstein: 10 to 20 cm; - remaining parts of the northern flank of the Alps, southern Valais, Prättigau: 5 to 15 cm; - in the other regions of Switzerland, it was generally dry. In the Jura region there was 15 to 30 mm of rainfall registered. Temperature: At midday at 2000 m: +1 °C in the northern regions, +3 °C in the Valais and in Grisons, and +5 °C in the central sector of the southern flank of the Alps. Wind: Winds in the northern regions were blowing at strong to storm strength from westerly to southwesterly directions, at high altitudes in particular blowing at moderate to strong velocity from westerly directions. During the night the precipitation will come to an end, including in the eastern regions. Subsequently, skies will clear up. During the daytime it will be predominantly sunny and very mild, with the exception of some intermediate-altitude cloudbanks in the northern regions. Fresh snow: In the northeastern regions, a few additional centimetres of fresh snow above approximately 2000 m. Temperature: At midday at 2000 m, between +7 °C in the northern regions and +4 °C in the southeastern regions. The zero-degree level will lie at 3000 m. Wind: Winds in the northern regions and in general at high altitudes will continue blowing at strong velocity from northwesterly directions, subsequently shifting to southwesterly.

Temperatures are expected to drop significantly. On Saturday in the northern regions, snowfall down to low lying areas is expected. On Sunday following an interim in precipitation, snowfall will once again set in. The snowfall level will ascend to over 1000 m. All in all in the northern regions, approximately 15 to 30 cm of fresh snow can be expected. The danger of dry-snow avalanches will stem largely from the freshly generated snowdrift accumulations. The danger of wet-snow avalanches will decrease significantly as the temperatures drop. In the southern regions it will be partly sunny and predominantly dry. Avalanche danger levels will decrease.