südliches Tujetsch

As a consequence of new snow and stormy weather a considerable avalanche danger will be encountered over a wide area.

Single snow sport participants can release avalanches in some places. These can be released in the weakly bonded old snow and reach large size in isolated cases. These avalanche prone locations are barely recognisable, even to the trained eye. In addition the fresh wind slabs are prone to triggering in some cases. Backcountry touring and other off-piste activities call for experience in the assessment of avalanche danger and careful route selection.

As a consequence of falling temperatures, the activity of wet avalanches will slowly decrease. The avalanche prone locations for wet avalanches are to be found in particular on steep east, south and west facing slopes below approximately 2600 m and on north facing slopes below approximately 2200 m. Medium-sized and, in isolated cases, large avalanches are possible.

Snowpack As a consequence of fresh fallen snow and strong-velocity winds, snowdrift accumulations which are prone to triggering are being generated at heightened altitudes. Deeply embedded inside the snow cover, particularly on west-facing, north-facing and east-facing slopes, there are expansively metamorphosed (faceted) layers evident over widespread areas. Avalanches can trigger in these layers and in some places can sweep away the entire snow cover. As a result of the fresh fallen snow, increasingly frequent avalanches are expected to be triggered in these weak layers. South-facing slopes are thoroughly wet up to over 3000 m. Also on west-facing slopes the snow cover is already thoroughly wet up to nearly 3000 m. On east-facing slopes the process of the snowpack becoming thoroughly wet up to between 2400 to 2800 m is continuing. On north-facing slopes, this is the case up to 1500 to 1800 m. As a consequence of the rainfall, north-facing slopes were superficially moistened up to 2500 m. With the descending temperatures, activity of wet-snow avalanches will incrementally decrease. Observed weather review Friday, 24.03.2023 Nighttime skies were predominantly overcast and precipitation set in from the west. During the daytime hours there was a small amount of precipitation over far-reaching areas. In Grisons it remained predominantly dry until afternoon and skies were partly bright. The snowfall level lay between 2000 m and 2500 m. Fresh snow Between Thursday evening and Friday afternoon, the following amounts of fresh snow were registered above 2000 m:

• northern and furthermost western part of the Lower Valais, Bedrettotal: 10 to 20 cm;
• remaining parts of Valais, remaining parts of northern Alpine Ridge: 5 to 10 cm; in the other regions of Switzerland, less or else it remained dry.

Temperature At midday at 2000 m, +4 °C in the northern regions and +2 °C in the southern regions. Wind Winds were blowing at moderate to strong velocity from southwesterly directions. Weather forecast through Saturday, 25.03.2023 In the northern regions, precipitation is anticipated over widespread areas. During the afternoon the precipitation will slacken off and bright intervals are expected. The snowfall level will descend from approximately 1800 m down to 1400 m. In the southern regions the nocturnal skies will be predominantly clear and during the daytime it will be quite sunny. Fresh snow Between Friday evening and Saturday afternoon, the following amounts of fresh snow are expected above 2200 m:

• furthermost western part of Lower Valais: 30 to 40 cm;
• remaining parts of Lower Valais, northern Alpine Ridge, northern Prättigau: 15 to 30 cm;
• in the remaining regions of Switzerland, 5 to 15 cm widespread.

Temperature At midday at 2000 m, between -2 °C in the northern regions and 0 °C in the southern regions. Wind Winds will be blowing at strong velocity, at elevated altitudes at storm strength in some places, from westerly directions. Outlook through Monday, 27.03.2023 Following a pause in this round of precipitation on Saturday night, precipitation will set in once again; on Sunday the focal point of precipitation will be in the furthermost western part of the Lower Valais, subsequently on Monday in the entire region of Lower Valais and on the northern Alpine Ridge. All in all, 40 to 60 cm of fresh fallen snow is anticipated in these regions, as much as 80 cm from place to place. The snowfall level on Sunday will lie between 1200 and 1600 m, subsequently descend on Monday down to low lying areas. Winds will continue to be blowing at strong to storm strength from westerly directions, on Monday from northwesterly directions. As a consequence of the precipitation, danger of dry-snow avalanches will increase still further. On Sunday in the furthermost western part of the Lower Valais, and on Monday also in the other major areas of precipitation, Danger Level 4 (high) can be reached over far-reaching areas. The danger of wet-snow avalanches will decrease as temperatures descend. Isolated gliding avalanches continue to be anticipated.