nördliches Urseren

In the west a high avalanche danger will be encountered in some regions

In the west a high avalanche danger will be encountered in some regions

The fresh and older wind slabs are in some cases prone to triggering. The avalanche prone locations are to be found in particular adjacent to ridgelines in all aspects and in gullies and bowls, and behind abrupt changes in the terrain. Avalanches can be released by a single winter sport participant. In isolated cases avalanches can be released in deep layers and reach medium size. This applies in particular on very steep north facing slopes in little used backcountry terrain. Experience in the assessment of avalanche danger is required.

The westerly winds, which will frequently be blowing at strong to storm velocity, will transport the snow intensively at high altitudes and subsequently wide-ranging snowdrift accumulations will be generated, including distant from ridgelines. As a consequence of the mild temperatures the snow has become superficially moist up to approximately 2500 m, and wet below 2000 m. As a result of dropping temperatures on Friday night, a process of snowpack stabilisation will set in. In the inneralpine regions of Grisons and in parts of the Valais, the snowpack structuring on north-facing slopes continues to be weak. Fractures extending down to deeply embedded layers are possible.

In the northern and the western regions skies were overcast and there was precipitation registered. In the southern regions and in Grisons, there were extended bright intervals in some places. The snowfall level ascended from 1600 m to approximately 2000 m. Fresh snow: Between Thursday afternoon and Friday afternoon, the following amounts of fresh snow were registered above approximately 2200 m: - Trient region and northern Lower Valais: 30 to 50 cm over widespread areas; - remaining parts of the northern Alpine Ridge from northern Chablais into the Haslital and remaining parts of Lower Valais: 20 to 30 cm over widespread areas; - remaining parts of northern flank of the Alps, remaining parts of Upper Valais, northern Ticino: 10 to 20 cm; - in the other regions of Switzerland, less; or else it remained dry. Between Wednesday afternoon and Friday afternoon, the following amounts of fresh snow were registered above approximately 2200 m: - northern and furthermost western parts of Lower Valais: 40 to 70 cm over widespread areas; - northern flank of the Alps, northern Upper Valais and from central Valais into Goms: 20 to 40 cm over widespread areas; - southern valleys of Visp, northern Ticino, northern Grisons: 10 to 20 cm; - in the remaining regions of Switzerland, less. Temperature: At midday at 2000 m, between +2 °C in the northern regions and +4 °C in the southern Valais, Ticino and Grisons. Wind: - Winds were westerly, - blowing predominantly at strong to storm strength at high altitudes, frequently at moderate to strong velocity on the southern flank of the Alps and in Grisons. In the northern regions skies will be heavily overcast for the most part and widespread snowfall in the form of showers is expected, intermittently intensive in the western regions. On the southern flank of the Alps it is expected to be rather sunny. Fresh snow: The snowfall level will swiftly descend down to low lying areas on Friday night. Between Friday afternoon and Saturday afternoon, the following amounts of fresh snow are anticipated at high altitudes: - furthermost western part of Lower Valais: 40 to 60 cm; - western sector of the northern flank of the Alps; - Lower Valais, central and eastern sectors of the northern flank of the Alps, as well as Bernina region: 15 to 30 cm; - in the other regions of Switzerland: 5 to 10 cm over widespread areas; in the furthermost southern regions it is expected to remain dry. Temperature: At midday at 2000 m, between -7 °C in the northern regions and -4 °C in the southern regions. Wind: Winds will shift from northwesterly to northerly, - initially be blowing at strong to storm strength in the mountains, subsequently slackening off during the course of the day; - in some areas of the southern regions, strong-velocity northerly winds extending down to the valleys.

In the western and the southern regions, skies on Saturday night will become increasingly clear. During the daytime on Sunday it will be predominantly sunny, accompanied by residual clouds in the eastern regions in early morning. Temperatures are expected to rise. On Monday it will be generally sunny and significantly warmer. The danger of dry-snow avalanches will decrease. The danger of wet-snow avalanches will become increasingly subject to a daytime danger cycle.