New snow
- Todas las altitudes
At high altitudes and in high Alpine regions a considerable avalanche danger will be encountered over a wide area.
The new snow and wind slabs are prone to triggering. Avalanches can in some cases be released easily and reach large size in isolated cases. Backcountry touring calls for experience in the assessment of avalanche danger and careful route selection.
The Avalanche Warning Service currently has only a small amount of information that has been collected in the field, so that the avalanche danger should be investigated especially thoroughly in the relevant locality.
As a consequence of the rain more medium-sized to large wet and gliding avalanches are possible. This applies in particular below approximately 2200 m.
Snowpack The fresh fallen snow lies deposited on top of a quite favourable old snowpack surface. As a consequence of additional snowfall, the danger of dry-snow avalanches will increase further in the northern and the eastern regions. Avalanches can be triggered in the fresh fallen snow and freshly generated snowdrift accumulations more than anywhere else. The old snow cover on north-facing slopes below approximately 2700 m, in the other aspects up to over 3000 m, is thoroughly wet. In the southern Valais and in Grisons, more than anywhere else, as well as from place to place in the other regions of Switzerland, there are still pronounced weakened layers evident deeply embedded inside the snow cover. During the last few days, these layers have been moistened for the first time during this winter season as a consequence of the mild temperatures and the rainfall and thereby weakened further. As a result of the descending temperatures, the activity of wet-snow avalanches has diminished. Gliding avalanches continue to be possible. Dry-snow avalanches can sweep away the entire moistened snow cover and thereby grow to large size. Observed weather review Wednesday, 10.05.2023 Precipitation has been registered over far-reaching areas, in the eastern regions more than anywhere else during the daytime hours. Further to the west, there were some bright intervals. The snowfall level descended from 2500 m down to nearly 2000 m. Fresh snow The following amounts of fresh snow have been registered in high alpine regions between Tuesday afternoon and Wednesday afternoon:
Temperature At midday at 2000 m, between +4 °C in the Valais and in the southern regions and +1 °C in the remaining regions of Switzerland. Wind Winds were blowing at light to moderate strength from westerly to northerly directions. Weather forecast through Thursday, 11.05.2023 Skies will be heavily overcast. Precipitation is anticipated over far-reaching areas, and will be persistent and intensive in the northern and the eastern regions. The snowfall region will lie between 1600 and 1800 m. Fresh snow The following amounts of fresh snow are anticipated above approximately 2300 m between Wednesday afternoon and Thursday afternoon:
Temperature At midday at 2000 m, between 0 °C in the northern regions and +4 °C in the southern regions. Wind Winds will be blowing at light to moderate strength from northerly directions. Outlook through Saturday, 13.05.2023 On both days, skies will be variably cloudy, accompanied by showers. Nocturnal skies will be overcast each night. During the daytime hours, some bright intervals are anticipated, particularly on Saturday. The snowfall level will lie at approximately 2000 m. Winds will be predominantly light. The danger of dry-snow avalanches is expected to decrease. Dry-snow avalanches can sweep away the entire moistened snow cover. Below 2200 m, wet-snow and gliding avalanches are possible.
Bulletin data: WSL Institute for Snow and Avalanche Research SLF (CC BY 4.0)