Waadtländer Voralpen

Weakly bonded old snow in the inneralpine regions

Weakly bonded old snow in the inneralpine regions

As a consequence of westerly wind, small wind slabs formed in particular in the vicinity of peaks. Individual avalanche prone locations for dry avalanches are to be found in particular on extremely steep shady slopes. Restraint should be exercised because avalanches can sweep people along and give rise to falls. Individual mostly small gliding avalanches are possible. Caution is to be exercised in areas with glide cracks.

In the lower part of the snowpack, particularly on west-facing, north-facing and east-facing slopes above approximately 2200 m, weak layers are evident. In the western Lower Valais and on the northern flank of the Alps these ground-level layers are covered over by thick layers of fresher snow so that the likelihood of avalanches being triggered by persons is low. From central Valais over the Ticino as far as Grisons, the snowpack layering is least favourable. In those regions, there have been medium-sized avalanches triggered by persons during the last few days. In the last few days only isolated gliding avalanches were reported. On shady slopes the upper part of the snow cover is expansively metamorphosed (faceted) and loose, in some places there is surface hoar blanketing the surface. This is an unfavourable snow base for the approaching snowfall. On south-facing slopes the snowpack surface shows marked effects of the sun and is more favourable for that reason.

Nocturnal skies were partly cloudy. During the daytime it was predominantly sunny. During the afternoon clouds moved in from the northwest. Fresh snow: - Temperature: At midday at 2000 m, +2 °C in the northern regions and -2 °C in the southern regions. Wind: Winds were blowing at moderate to strong velocitdy, in the inneralpine regions and in the south at light to moderate strength, from westerly directions. Skies will be predominantly overcast. During the afternoon, a bit of snowfall is expected above 1800 m. Fresh snow: - Temperature: At midday at 2000 m, 0 °C in the northern regions and -2 °C in the southern regions. Wind: Winds will be blowing at moderate to strong velocity from westerly directions.

On Christmas Day and on Boxing Day, skies will be predominantly overcast. Repeated bouts of minor snowfall are anticipated. On Christmas Day the snowfall level will lie at approximately 1600 m, on Boxing Day at 1200 m. The small amount of fresh fallen snow will be deposited on top of a very unfavourable snowpack surface on shady slopes in particular. The danger of dry-snow avalanches is expected to increase somewhat.