Emosson

Moderate avalanche danger will prevail. Wind slabs are to be evaluated with care and prudence

Moderate avalanche danger will prevail. Wind slabs are to be evaluated with care and prudence

The northerly wind has transported the new snow. The wind slabs of Wednesday are in some cases still prone to triggering. They are to be evaluated with care and prudence in steep terrain. At elevated altitudes the avalanche prone locations are more prevalent. In particular in southern Valais avalanches can be triggered in the weakly bonded old snow and reach medium size. These avalanche prone locations are rare but are barely recognisable, even to the trained eye. Caution is to be exercised in particular on little-used, rather lightly snow-covered shady slopes. Defensive route selection is advisable.

The fresh snow from the last few days and the snowdrift accumulations which were generated by frequently strong winds have been deposited on top of an old snowpack surface which manifests striking effects of rain, wind and snow, in some places is also iced over.In the central Valais over the northern Ticino as far as Grisons, more than anywhere else, very isolated avalanches can be triggered in the old snow at high altitudes. This applies to expansively metamorphosed (faceted) loose-snow layers either immediately beneath the rain crusts which formed at the end of December or in layers more deeply embedded inside the snowpack.

During the nocturnal hours skies were overcast and in the eastern regions there was a small amount of fresh snow registered down to the flatlands. During the daytime in the western and the southern regions it was predominantly sunny. In the northeastern regions skies remain overcast, but for the most part dry. Fresh snow: in the eastern sector of the northern flank of the Alps and in Val Müstair, only a few centimetres. Temperature: At midday at 2000 m, between -8 °C in the northern regions and -6 °C in the southern regions. Wind: - During the nocturnal hours winds were blowing at moderate to strong velocity, on the Main Alpine Ridge storm-strength northerly to northwesterly winds in some places; - during the daytime, slackening off somewhat. Nighttime skies will be predominantly clear. In early morning in the eastern regions, extended bright intervals are anticipated, in the other regions of Switzerland skies will be overcast during the daytime. In the northern regions during the afternoon, a small amount of snowfall is expected to fall down to low lying areas. In the southern regions it will be quite sunny. Fresh snow: On the northern flank of the Alps, in the Lower Valais and the Jura region, only a few centimetres. Temperature: At midday at 2000 m, -8 °C. Wind: - Winds during the nighttime hours will be blowing at light strength; - during the daytime blowing at moderate strength, in the afternoon blowing at strong velocity from place to place, from westerly to northwesterly directions.

On the weekend skies are expected to be heavily overcast, accompanied by precipitation. Only in the furthermost southern regions will it be dry and predominantly sunny. Most of the precipitation is anticipated in the northern and the western regions. Approximately 10 to 20 cm of fresh snow is expected there by Saturday afternoon, although the amounts of expected precipitation are still uncertain. On Sunday afternoon, an additional 20 to 40 cm of new fallen snow will be added to it. The westerly to northwesterly winds will frequently be blowing at strong velocity, on Saturday night at storm strength. In the northern and the western regions, avalanche danger is expected to increase significantly, and on Sunday increasingly frequent naturally triggered avalanches can be expected. In the remaining regions of Switzerland, avalanche danger levels will increase slightly; in the furthermost southern regions the avalanche danger levels are not expected to change significantly.