Untere Maggiatäler

In northern Lower Valais, there is somewhat more snow at high altitudes than is usual at this time of year. Elsewhere, the snow depths are below average. On southern slopes and generally below 2400 m, the snowpackSnow deposited on the ground in a multiplicity of layers.EAWS glossary is mostly wet or has frozen solid.

On the Main Alpine Ridge and to the south of it, this week’s fresh snow is lying at altitude on a thin but weak old snowpackSnow layers deposited from earlier precipitation, prior to fresh fallen snow. Old snow layers consist of metamorphosed snow crystals.EAWS glossary of faceted crystalsSnow grains, solid, with multiple flat glassy faces and sharp edges. Developed from faceting metamorphism, usually poorly bonded to one another (fewer contact points), a critical factor in avalanches if a faceted layer is covered with bonded snow. Typical grain size: 0.5 to 3 mm See also: www.snowcrystals.itEAWS glossary.

North of the Main Alpine Ridge, small wind slabs have formed at altitude in some regions. Some of them lie on surface hoarTransparent, frequently flat crystals forming on the snowpack when moist air settles on the surface. It forms most often during cold, clear, humid nights. Once it is blanketed by fresh fallen snow, surface hoar is one of the most critical weak layer. See also: www.snowcrystals.itEAWS glossary (hoar frost) and can still be triggered as avalanches. In addition, in the inneralpine regions of Valais and throughout Grisons in particular, there are some 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 deeper in the old snowpackSnow layers deposited from earlier precipitation, prior to fresh fallen snow. Old snow layers consist of metamorphosed snow crystals.EAWS glossary, especially on northern and eastern slopes above approximately 2400 m. However, hardly any avalanches have been triggered in these layers for some days.

In Valais and Sotto Ceneri there were some clear spells, otherwise it was mostly cloudy.

Fresh snow

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Temperature

At midday at 2000 m, between +3 °C in the north and 0 °C in the south

Wind

• Moderate to strong from southerly directions during the night
• Light to moderate from the southwest during the day

It will be quite sunny in the mountains in the the north and in the Engadine. It will often be cloudy on the central part of the Main Alpine Ridge and on the central part of the southern flank of the Alps.

Fresh snow

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Temperature

At midday at 2000 m, around +2 °C

Wind

Often light. Moderate southerly wind at times on the Main Alpine Ridge

On Sunday and Monday, it will be partly sunny and mild in the north. The southerly wind will be strong on Sunday and moderate to strong on Monday. In the Alpine valleys, there will be a strong foehn wind at times. In the south, snow will fall at times above approximately 1300 m. By Monday evening, 20 to 40 cm of new snow is expected on the Main Alpine Ridge in Upper Valais and 10 to 20 cm on the Main Alpine Ridge in the rest of Valais and in Ticino.

The avalanche danger will increase in the south with the arrival of new snow. It will not change significantly in the other regions.