Martigny-Verbier

Considerable avalanche danger will be encountered over a wide area

Considerable avalanche danger will be encountered over a wide area

The new snow and wind slabs are lying on top of a weakly bonded old snowpack. Avalanches can be released, even by a single winter sport participant. Remotely triggered avalanches are possible. Whumpfing sounds can indicate the danger. Avalanches can be triggered in near-ground layers and reach large size. Defensive route selection is important.

Last week 150 to 200 cm of snow fell above approximately 2000 m over a wide area of the north and of the far west; elsewhere 40 to 100 cm fell over a wide area. The fresh snow and snow drift accumulations originating from this period is lying on a shallow, soft old snowpack containing faceted snow crystals. The bonding of the snowpack is therefore unfavourable, in particular on west, north and east facing slopes above 2000 m. Most avalanches of recent days were released in this weak old snow. On Tuesday in the north, a northwesterly wind will transport fresh and loosely bonded old snow, and snow drift accumulations will form.

On Sunday night in the north a little snow fell over a wide area. During the day it was cloudy at first. It then became increasingly sunny from the west, except in the eastern part of the northern flank of the Alps and in northern Grisons. The south was dry and sunny all day. Fresh snow: From Sunday evening until Monday morning: - A few centimetres in the north - Dry in Valais, Grisons and the south Temperature: At midday at 2000 m: about -9 °C in the north and -6 °C in the south Wind: Light to moderate from northerly directions On Monday night a little snow will fall in the north, even at low altitudes. In the course of the morning it will become increasingly sunny from the west. The south will be dry and mostly sunny during the day. Fresh snow: From Monday night until Tuesday midday: - 5 to 10 cm over a wide area, but locally up to 15 cm - Dry in the south Temperature: - Increasing as the day progresses - At midday at 2000 m: between -3 °C in the west and -9 °C in the east and south Wind: - Moderate to strong from the west to northwest - Easing in the afternoon

Wednesday: On Tuesday night, precipitation will arrive from the west; it will become heavier during the day. The snowfall level will be approximately 800 m, but also higher for a while. In the northern valleys the foehn-like conditions will persist in the morning, otherwise there will be a strong southwesterly wind for a while. In the south at elevated altitudes there will be a moderate, but sometimes strong, southerly wind. The avalanche danger will increase, in particular in the west. Thursday: On Wednesday night the precipitation will cease. During the day it will remain frequently cloudy; in the south and in Valais it will be partly sunny. The wind will be moderate to strong from northwesterly directions. The avalanche danger will not change significantly.