Martigny-Verbier

The snow depths at intermediate and high altitudes are generally below average for the time of year. There is particularly little snow on the southern flank of the Alps. Only in parts of Lower Valais is snow depth roughly in line with the long-term average. On southern slopes and generally below 2400 m, the snowpackSnow deposited on the ground in a multiplicity of layers.EAWS glossary is mostly crusted.

Along the Main Alpine Ridge and south of there, fresh and drifted snow will be deposited at high altitudes on a thin but heavily faceted snowpackSnow deposited on the ground in a multiplicity of layers.EAWS glossary on Tuesday. Avalanches are particularly likely to be triggered in these regions.

North of the Main Alpine Ridge, there are pronounced weak layersSnowpack layer in which the crystals are poorly bonded and the layer has the potential to fail. Typical crystals in dry weak layers causing avalanches are : precipitation particles; surface hoar; faceted crystals; hollow crystals; graupel. Generally >1mm in size, loose grains with few bonds Wet weak layers can be formed by all snow crystal/grain types.EAWS glossary in the snowpackSnow deposited on the ground in a multiplicity of layers.EAWS glossary, particularly on northern and eastern slopes above approximately 2400 m, but hardly any avalanches have been triggered there in recent days by human activity. At high altitudes the strong southerly wind may transport some of the old snowpackSnow layers deposited from earlier precipitation, prior to fresh fallen snow. Old snow layers consist of metamorphosed snow crystals.EAWS glossary, resulting in snowdrift accumulations locally prone to triggering.

Conditions were mostly sunny in the mountains, with high broken cloud gathering in the south-west and south from midday.

Fresh snow

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Temperature

At midday at 2000 m, between +4°C in the north and +1°C in the south

Wind

In the Alpine valleys in the north and generally at high altitudes, moderate, at times strong from southerly directions

Towards Tuesday morning, precipitation will set in on the Main Alpine Ridge and south of there. The snowfall level will be at around 1200 m. In other regions, it will be mostly cloudy but dry.

Fresh snow

The following amounts will fall above 1600 m by Tuesday afternoon:

• Main Alpine Ridge from the Grand St Bernard Pass to the Bernina and south of there: 5 to 15 cm, with up to 20 cm in western Ticino and the Simplon region
• elsewhere dry

Temperature

At midday at 2000 m, between +4°C in the north and -2°C in the south

Wind

In the Alpine valleys in the north and generally at high altitudes, at times strong from southerly directions

During the night to Wednesday and on Wednesday morning it will be cloudy on the southern flanks of the Alps and in Grisons. Some snow may fall above 1600 m. In other regions, Wednesday will be very sunny. On Thursday conditions will be very cloudy but dry on the southern flank of the Alps, with sunny conditions elsewhere. Winds will be mostly light on Wednesday, and occasionally moderate on Thursday, from the southwest.

Avalanche risk may continue to increase slightly during the night to Wednesday on the southern flank of the Alps, but elsewhere will barely change.