nördliches Urseren

As a consequence of new snow a considerable avalanche danger will be encountered over a wide area

As a consequence of new snow a considerable avalanche danger will be encountered over a wide area

The new snow and wind slabs are in some cases prone to triggering at elevated altitudes. As a consequence of a strengthening northeasterly wind, further wind slabs will form in the course of the day. Single snow sport participants can release avalanches, including medium-sized ones. Backcountry touring and other off-piste activities call for experience in the assessment of avalanche danger.

The fresh snow which fell this week is generally well bonded with the old snowpack surface. Avalanches can be triggered in particular inside the layers of fresh fallen snow and newly generated snowdrift accumulations. As a result of the fresh snow and northeasterly winds, additional snowdrift accumulations will be generated on Saturday. The old snowpack on north-facing slopes below approximately 1800 m, on east-facing slopes below approximately 2500 m, on south-facing slopes up to over 3000 m, and on west-facing slopes below approximately 2800 m, is thoroughly wet. Prior to the current rounds of snowfall in the northern regions on north-facing slopes above approximately 1000 to 1400 m, in the southern regions above approximately 1800 to 2200 m, there was a cohesive, area-wide snowpack. On south-facing slopes the snow line lay mostly 300 to 500 m higher up. Over widespread areas there is significantly less snow on the ground than is usual for this juncture of the season, in the southern regions extraordinarily less snow on the ground.

Skies were heavily overcast, accompanied by shower-like snowfall. Most of the fresh snow fell on the northern flank of the Alps. During the course of the day in the southern regions there were isolated bright intervals. The snowfall level in northern regions descended to approximately 600 m, in the southern regions it sank to approximately 1300 m. Fresh snow: Between Thursday afternoon and Friday afternoon on the northern flank of the Alps, in the western part of the Lower Valais and in northern Grisons, 15 to 25 cm of fresh snow was registered, 30 cm in the western Bernese and Central Swiss Alps. Overall between Wednesday morning and Friday afternoon, the following amounts of fresh snow were registered above approximately 2000 m: - Northern flank of the Alps from Les Diablerets as far as the Glarus Alps: 25 to 35 cm; - remaining regions on the northern flank of the Alps and in the Lower Valais, northern and central Grisons, Engadine: 15 to 25 cm; - in the other regions of Switzerland, 5 to 15 cm; on the southern flank of the Alps only a few centimetres. Temperature: At midday at 2000 m, between -6 °C in the northern regions and -3 °C in the southern regions. Wind: Winds were blowing at light to moderate strength, at moderate-to-strong velocity at the heights of the Jura, from northerly directions. In the northern regions skies will be heavily overcast, and snowfall is expected down to low lying areas. In the southern regions skies will be variably cloudy accompanied by sunny intervals and with showers. Fresh snow: Between Friday afternoon and Saturday afternoon above approximately 1500 m: - Northern flank of the Alps, Valais not including Goms: 15 to 30 cm over widespread areas, more from place to place in the eastern Bernese and Central Swiss Alps; - Jura region, Goms, Grisons not including Moesano: 10 to 20 cm; - Ticino, Moesano: 5 to 10 cm. Temperature: Temperatures are expected to drop. At midday at 2000 m in the northern regions, -10 °C, and in the southern regions -6 °C. Wind: Winds will be predominantly moderate, at the heights of the Jura and on the Alpine ridges often blowing at strong velocity, from northerly to northeasterly directions.

Sunday: On Saturday night in the northern regions there will be a small amount of snowfall extending down to low lying areas. During the daytime on Sunday the cloud cover will disperse in the northern regions and somewhat brighter skies are anticipated. In the inneralpine and southern regions it will be partly sunny. In the south during the afternoon, showers are possible. The northerly-to-northeasterly winds will slacken off during the course of the day. The danger of dry-snow avalanches is not expected to change significantly. As a result of the solar radiation, moist slides from the fresh fallen snow will be possible on steep sunny slopes. Monday: In the northern regions it will be sunny, following a night of predominantly clear skies. In the southern regions, nocturnal skies on Sunday will be predominantly overcast and above approximately 800 m there will be a small amount of snowfall. During the course of the day on Monday it will become increasingly sunny. The danger of dry-snow avalanches is expected to decrease. The danger of moist avalanches will increase during the course of the day.