Waadtländer Voralpen

Distinct weak layers in the old snowpack necessitate caution.

Avalanches can be triggered in the weakly bonded old snow and reach medium size. These avalanche prone locations are to be found especially on very steep shady slopes above approximately 2000 m and in gullies and bowls. They are rather rare but are difficult to recognise. Isolated whumpfing sounds can indicate the danger. In addition mostly small wind slabs will form in particular adjacent to ridgelines and in pass areas and at elevated altitudes as the day progresses. Snow sport activities outside marked and open pistes call for careful route selection.

As a consequence of warming during the day and solar radiation gliding avalanches and moist snow slides are to be expected.

Snowpack Fresh fallen snow and freshly generated snowdrifts from the last few days were deposited on top of a weak old snowpack surface above approximately 2000 m and are easily triggered in some places. The basis of the snow cover is expansively metamorphosed (faceted) and loose over widespread areas. Avalanches can fracture down to deeply embedded layers inside the snowpack. Below approxmately 2000 m the snowpack on the northern flank of the Alps and in the Jura region shows pronounced effects of the higher tamperatures. Observed weather review Saturday, 17.12.2022 During Friday night in the eastern regions in particular, there was an additional small amount of snowfall down to low lying areas. In the remaining regions of Switzerland skies were intermittently clear. During the daytime hours on Saturday it was sunny in the mountains. Fresh snow In Grisons as much as 10 cm, in the other regions less, or else it remained dry. Temperature At midday at 2000 m, -3 °C in the western regions, -8 °C in the eastern regions and -1 °C in the southern regions. Wind

• Winds on the Main Alpine Ridge were blowing at moderate strength from northwesterly directions;
• in the other regions of Switzerland, mostly light winds.

Weather forecast through Sunday, 18.12.2022 Following a night of clear skies it is expected to be predominantly sunny during the daytime. In the afternoon, heavy high-altitude clouds will move in from the northwest. Fresh snow - Temperature At midday at 2000 m, +4 °C in the northern regions and +1 °C in the southern regions Wind Winds will be lighter during the nocturnal hours, during the daytime hours blowing at moderate strength at elevated altitudes, in the Jura region often stronger, from southwesterly directions. Outlook through Tuesday, 20.12.2022 On Monday and on Tuesday it will be predominantly sunny in spite of high-altitude cloudbanks passing through. It will be extraordinarily mild. The zero-degree level will lie between 3200 and 3600 m. At high altitudes a moderate-strength, in the Jura region frequently a strong velocity southwesterly wind will be blowing. The danger of dry-snow avalanches will decrease only incrementally due to the persistent weak layer problem which extends over far-reaching areas. During the course of the day as a result of the higher temperatures and solar radiation, gliding avalanches and moist-snow avalanches can be expected.