Bex-Villars

A generally favourable avalanche situation will prevail. Fresh wind slabs require caution

A generally favourable avalanche situation will prevail. Fresh wind slabs require caution

As a consequence of foehn wind, mostly small wind slabs formed. These are lying on the unfavourable surface of an old snowpack on north facing slopes. They are easy for the trained eye to recognise but can be released easily. Mostly the avalanches are small. 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.

Recently generated snowdrift accumulations are evident particularly in the foehn-exposed regions of the north. The accumulations have been deposited on north-facing slopes more than anywhere else, on top of expansively metamorphosed (faceted) old snow and are prone to triggering in some places. In spite of strong-velocity southerly winds and foehn wind in many places, hardly any further snowdrift accumulations are being generated, since there is simply too little snow to be transported. More deeply embedded inside the snowpack in the southern Valais as well as in the inneralpine and the southern regions of Grisons, there are pronounced weak layers evident. Since the end of February, however, no further avalanche releases have been recorded as triggering in these layers. In the eastern regions, the nocturnal longwave outgoing radiation is adequate, so that on steep south-facing slopes a crust forms which is capable of bearing loads. In the remaining regions of Switzerland the nighttime outgoing radiation is reduced. As a consequence of solar radiation and daytime warming, wet slides and gliding avalanches are possible north of an imaginary Rhine-Rhone line on very steep, sunny slopes more than anywhere else.. 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 consequence 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.

On Friday night in the western and the southern regions there was a small amount of snowfall which extended down to low lying areas. During the daytime on Saturday, skies were predominantly overcast in the southern regions, in the other regions of Switzerland it was quite sunny, accompanied by high-altitude cirrus clouds. Fresh snow: - Temperature: At midday at 2000 m, between -1 °C in the northern regions and -7 °C in the southern regions. Wind: Winds in the foehn-exposed regions of the north were blowing at moderate to strong velocity, in the other regions at light-to-moderate strength, from southerly directions. Skies on Saturday night will be predominantly clear in the eastern regions. In the western regions skies will be partly overcast. In the southern regions, skies will be overcast. During the daytime hours on Sunday in the western regions and in the Valais section of the Main Alpine Ridge, skies will be predominantly overcast. There, a small amount of snowfall is possible. In the southern regions it will be partly sunny, in the eastern regions predominantly sunny. Fresh snow: A small amount of snowfall is possible in the Valais section of the Main Alpine Ridge. Temperature: At midday at 2000 m, between +3 °C in the northern regions and -6 °C in the southern regions. Wind: - Winds on the northern Alpine Ridge and at high altitudes in general will be blowing at moderate to strong velocity from southerly directions; - in the foehn-exposed regions of the north, winds will be blowing at moderate strength, strong foehn winds are expected during the afternoon.

On Monday it will be rather sunny, following a night of predominantly overcast skies in the northern regions. In the southern regions, a small amount of snowfall is expected during the nocturnal hours, extending down to low lying areas. During the daytime on Monday skies will remain overcast. Winds will slacken off and be blowing predominantly at moderate strength from southwesterly directions. On Monday night in the southern regions, another bout of snowfall is anticipated, bringing a small amount of fresh snow. During the daytime on Tuesday, skies will frequently be overcast on both sides of the Alps. As a consequence of strong-velocity southwesterly winds, it will become significantly milder. The avalanche situation is not expected to change significantly. The snowdrift accumulations which have been generated by foehn winds are gradually stabilising. Isolated avalanche prone locations in the old snow occur particularly on very steep, shady slopes in the inneralpine regions. North of an imaginary Rhine-Rhone line more than anywhere else, gliding avalanches are possible. As a result of the milder temperatures and the reduced nocturnal longwave outgoing radiation, the danger of wet-snow avalanches tends to increase somewhat during the course of the day.