Guttannen

A generally favourable avalanche situation will prevail. Fresh wind slabs in the regions of the north that are exposed to the foehn wind

A generally favourable avalanche situation will prevail. Fresh wind slabs in the regions of the north that are exposed to the foehn wind

As a consequence of foehn wind, rather small wind slabs will form. These are lying on the unfavourable surface of an old snowpack on north facing slopes. Avalanches can in some places be released by a single winter sport participant, but they will be small in most cases. Apart from the danger of being buried, restraint should be exercised as well in view of the danger of avalanches sweeping people along and giving rise to falls. Gliding avalanches are possible in isolated cases. In particular on steep sunny slopes they can be released naturally and reach medium size. Areas with glide cracks are to be avoided as far as possible.

As a consequence of strong-velocity southerly foehn wind in some places, snowdrift accumulations will be generated from place to place, in particular on north-facing slopes in the foehn-influenced regions. These snowdrifts will be deposited atop expansively metamorphosed (faceted) snowpack surfaces and are prone to triggering. More deeply embedded inside the snowpack in the southern Valais and in the inneralpine and southern regions of Grisons, there are weak layers evident. Even though these weak layers are quite pronounced from place to place, there have been no further avalanches recorded as triggering from these layers since the end of February. In the remaining regions of Switzerland the snowpack structuring is more favourable. In the western and the southern regions, nocturnal skies will be frequently overcast and the outgoing longwave radiation reduced. Thereby, a crust which is rarely capable of bearing loads will be formed on steep south-facing slopes. In the eastern regions and in Grisons, nighttime skies are predominantly clear and the outgoing longwave radiation adequate. As a result of solar radiation and daytime warming, wet slides and gliding avalanches are possible, particularly on the northern flank of the Alps and on very steep sunny slopes. In the southern regions there is unusually little snow on the ground, at numerous measurement stations less than has ever before been measured at this juncture of the season. As a result of the shallow, often expansively metamorphosed (faceted) snowpack there is currently heightened danger of falling into crevices on the glaciers, most particularly in the southern Valais and in southern Grisons.

Following a night of clear skies, it was sunny during the daytime hours. Fresh snow: - Temperature: At midday at 2000 m, between +4 °C in the western regions and 0 °C in the furthermost eastern regions. Wind: Winds were blowing at light strength. On Thursday night, nocturnal skies in the eastern regions will be predominantly clear, in the western and the southern regions skies will be partly overcast. During the daytime on Friday, it will be generally sunny in the eastern regions, in the western regions it will initially be quite sunny, but during the course of the day cloud cover will move in. In the southern regions skies will be predominantly overcast. A small amount of snowfall is possible above 600 m. Fresh snow: In the central sector of the southern flank of the Alps, a few centimetres of fresh snow is possible above 600 m. Temperature: At midday at 2000 m, between +1 °C in the northern regions and -7 °C in the southern regions. Wind: - Winds on the northern Alpine Ridge and on the Main Alpine Ridge will be blowing at moderate strength, at strong velocity in some places, from southwesterly directions; - in the foehn-exposed regions of the north, a moderate-to-strong velocity southerly foehn wind will be blowing.

In the Jura region, skies will frequently be overcast on both days. In the western regions, skies will be partly overcast, in the eastern regions and in Grisons it will be predominantly sunny. In the Ticino, a small amount of snowfall is anticipated on Friday night, falling down to low lying areas. During the daytime on Saturday, skies are expected to brighten and on Sunday it will be quite sunny. Winds will be blowing from southwesterly directions. On Saturday in particular, foehn winds will be blowing in the northern regions, frequently at strong velocity. The avalanche situation is not expected to change significantly. In the foehn-influenced regions and at high altitudes in general, the freshly generated snowdrift accumulations require caution. These snowdrifts are prone to triggering particularly on north-facing slopes. Isolated avalanche prone locations in the old snow occur especially on very steep, shady slopes in the inneralpine regions. North of an imaginary Rhine-Rhone line, more than anywhere else, gliding avalanches will be possible.