Martigny-Verbier

In the west and in the north a considerable avalanche danger will be encountered over a wide area, especially at elevated altitudes

In the west and in the north a considerable avalanche danger will be encountered over a wide area, especially at elevated altitudes

The new snow and wind slabs of the last few days are lying on top of a weakly bonded old snowpack in particular on steep north facing slopes. Avalanches can be released by a single winter sport participant. These can penetrate deep layers and reach large size. The wind slabs are covered with new snow in some cases and therefore difficult to recognise. Backcountry touring and other off-piste activities call for experience in the assessment of avalanche danger. As a consequence of warming during the day and solar radiation more frequent small to medium-sized wet avalanches are to be expected. This applies in particular on very steep east, south and west facing slopes below approximately 2600 m.

The huge amounts of fresh snow which fell in the western and northern regions during the last few days are stabilising rapidly up to high altitudes. In the high alpine regions, the favourable development is proceeding somewhat more slowly. The fresh fallen snow and freshly generated snowdrifts increase significantly in quantity with ascending altitude. Particularly on north-facing slopes, the fresh fallen snow and freshly generated snowdrifts were deposited atop a loosely-packed snow cover surface. The snowpack surface in other aspects was more favourable. In the inneralpine regions of Grisons and in parts of the Valais, the snowpack structuring on north-facing slopes continues to be weak. Fractures reaching down to more deeply embedded layers of the snowpack are possible.

During Saturday night there was snowfall on the northern flank of the Alps more than anywhere else. Final showers in the eastern regions fell at about midday. Subsequently it became increasingly sunny. In the western and the southern regions, there was sunshine all day long. Fresh snow: The snowfall level lay at 600 m. Between Saturday evening and the end of this period of precipitation, the following amounts of fresh fallen snow were registered: - Glarus and St. Gallen Alps: 20 to 30 cm; - northern Lower Valais, remaing parts of the eastern sector of the northern flank of the Alps: 10 to 20 cm; - remaining parts of northern flank of the Alps, northern Grisons: predominantly 5 to 10 cm; - in the remaining regions of Switzerland, less. Throughout the entire period of precipitation between Wednesday afternoon and Sunday morning, the following amounts of fresh snow were registered above approximately 2200 m: - northern and furthermost western parts of Lower Valais from Trient region as far as the Wildstrubel: 60 to 80 cm; also more than 100 cm from region to region; - northern flank of the Alps, remaining parts of Valais not including upper valleys of Visp: 40 to 60 cm; - upper valleys of Visp, southern Gotthard region, northern Grisons: 20 to 40 cm; - remaining parts of northern Ticino, central Grisons, Engadine north of the Inn: mostly 10 to 20 cm; - in the remaining regions of Switzerland, less; or else it remained dry. In the prealps there was 20 to 40 cm of fresh snow registered between Friday night and Sunday above 1600 m. Temperature: Temperatures were rising. At midday at 2000 m, between -3 °C in the western and the southern regions and -7 °C in the northern and the eastern regions. Wind: Winds were blowing from northerly directions, - at moderate to strong velocity during the nocturnal hours at high altitudes; - blowing predominantly at light strength during the daytime hours, at moderate strength in some places at high altitudes. Nighttime skies on Sunday night will be predominantly clear and cold. During the daytime on Monday it will be generally sunny. Fresh snow: - Temperature: Temperatures are expected to rise noticeably. At midday at 2000 m: between +5 °C in the northern regions and +1 °C in the southern regions. Wind: Winds will be blowing predominantly at light strength, often at moderate strength at high altitudes, from southwesterly directions.

Tuesday: On Monday night, skies will be only partially clear. In early morning on Tuesday, it will be partly sunny. During the course of the day the cloud cover and gloominess from Sahara dust will increase. The zero-degree level will lie at approximately 3400 m. The danger of dry-snow avalanches will presumably decrease. The danger of wet-snow avalanches will increase and be subject to a daytime danger cycle. Wednesday: On Tuesday night, skies will be heavily overcast for the most part. During the daytime on Wednesday it will be only partly sunny. The zero-degree level will lie at approximately 3200 m. The danger of dry-snow avalanches is expected to diminish. The danger of wet-snow avalanches will remain at heightened levels.