Zervreila

Considerable danger of dry and wet avalanches will be encountered over a wide area.

The wind slabs of the last few days are lying on top of a weakly bonded old snowpack in particular on north facing slopes at elevated altitudes. Avalanches can in some places be released by people and reach medium size. Isolated whumpfing sounds can indicate the danger. Backcountry touring calls for defensive route selection.

Snowpack On north-facing and east-facing slopes above approximately 2200 m more than anywhere else, weak layers continue to lurk inside the old snow cover. In the western and the northern regions there was a great deal of fresh fallen snow registered at the beginning of the week, so that avalanches could still be triggered in the old snowpack in isolated cases, most likely in places where the snow was shallow. In the regions where there was less snow on the ground in general, from the southern Valais as far as Grisons, the weak old snow cover is not blanketed by as much fresh snowfall, therefore, fractures in the weak old snow cover are easier to trigger by winter sports enthusiasts. As a consequence of rainfall, the snow cover below 2400 m is weakened. North-facing slopes above approximately 2000 m where the weak snow cover was still dry prior to the current round of precipitation are most critical of all. Observed weather review Wednesday, 29.03.2023 On Wednesday in the furthermost southern regions it was predominantly sunny, in the other regions of Switzerland skies were overcast and there was intermittent precipitation registered. The snowfall level ascended from 1200 m to 2000 m, in the furthermost western regions to 2200 m. Fresh snow Between Tuesday afternoon and Wednesday afternoon, the following amounts of fresh fallen snow were registered above approximately 2500 m:

• northern Alpine Ridge from the Gemmi as far as Hausstock: 10 to 15 cm; in the Jungfrau region as much as 30 cm;
• in the remaining regions of Switzerland maximum 10 cm over widespread areas; in the furthermost southern regions it remained dry.

Temperature At midday at 2000 m, +2 °C. Wind

• Winds were frequently blowing at strong velocity, in some places at storm strength, from westerly directions;
• in the Ticino blowing at moderate strength from northwesterly directions.

Weather forecast through Thursday, 30.03.2023 Skies will be predominantly overcast accompanied by bright intervals along the Main Alpine Ridge in particular. A small amount of precipitation is anticipated in the form of showers over widespread areas. The snowfall level will ascend in western regions to 2500 m during the nocturnal hours, and in eastern regions to 2200 m; subsequently the snowfall level will descend down to approximately 2000 m. Fresh snow Between Wednesday afternoon and Thursday afternoon, a few centimetres of fresh snow is anticipated above 2600 m. In the southern regions it is expected to remain dry. Temperature Temperatures at 2000 m:

• during the nighttime hours in the northern regions: +8 °C;
• at midday, between +4 °C in the northern regions and +1 °C in the southern regions.

Wind

• Winds will be blowing at strong velocity, in southern regions at moderate strength, from westerly to southwesterly directions;
• in the northern regions, foehn wind will be blowing during the night.

Outlook through Saturday, 01.04.2023 Friday Skies will frequently be overcast, accompanied by precipitation. Most of the anticipated snowfall will be in the western regions (20 to 30 cm of fresh snow expected) and on the French border (up to 40 cm). The snowfall level will descend from 2000 m down to 1600 m. Winds in the northern regions and in general at heightened altitudes will be blowing at strong to storm-velocities from westerly directions. Avalanche danger levels are expected to increase slightly over far-reaching areas, more significantly in the western regions. Saturday In the furthermost southern regions it is expected to be sunny, in the other regions of Switzerland heavily overcast skies everywhere, accompanied by precipitation. On the northern Alpine Ridge and in the Lower Valais, approximately 20 to 40 cm of fresh fallen snow is expected, in the furthermost western regions still more fresh snow. Nevertheless, these prognosticated amounts of fresh snow are as yet uncertain. The snowfall level will descend to 1300 m. Winds in the northern regions and in general at elevated altitudes will continue to be blowing at strong to strom strength from westerly directions. Avalanche danger levels are expected to further increase in the northern and in the western regions, making conditions in zones apart from the secured ski runs critical for winter sports enthusiasts. Depending on the amounts of actual precipitation, Danger Level 4 (“high”) could be reached in the furthermost western regions. Only in the regions south of the Main Alpine Ridge will the avalanche situation remain predominantly favourable.