Val Sumvitg

Snowpack

After mild weather, overcast nights and rain in some regions, the snowpack has become increasingly water-saturated in recent days. On southern slopes, the snowpack is water-saturated up into the high Alpine regions, while on eastern and western slopes, the majority is water-saturated up to around 2800 m. On northern slopes, water saturation is under way up to altitudes of around 2400 m.

With large volumes of fresh snow and southeasterly winds, large snowdrift accumulations are forming above around 2500 m. This overlying snow can be expected to cause fractures in the old snowpack, in particular on northern slopes. This is especially the case in southern Valais, Ticino and in some regions of Grisons, where there are faceted layers deeper in the snowpack, but also in isolated cases in other regions.

Precipitation will be exceptionally heavy from Wednesday to Thursday midday in those regions most exposed to precipitation, causing a rapid increase in avalanche risk, especially overnight to Thursday.

Weather forecast to Thursday

Precipitation in the south and west will remain very heavy until midday on Thursday. The snowfall level will be between 1400 and 1600 m on the western part of the northern flank of the Alps and in Lower Valais, between 1600 and 2000 m on the central part of the northern flank of the Alps and in Upper Valais, and between 2000 and 2400 m on the central part of the southern flank of the Alps and in central and southern Grisons. In the northeast, conditions will remain mostly dry and there will be clear spells, both overnight and during the day.

Fresh snow

Snowfall above around 2400 m by Thursday afternoon:

• Main Alpine Ridge of Valais, Visp valleys, Aletsch region, Val Bedretto: 100 to 150 cm, and from the Monte Rosa region via the Saas valley and the Simplon region into Binntal up to 200 cm
• rest of Valais, rest of Northern Alpine Ridge west of the Reuss, Valle Maggia, Valle Leventina: 50 to 100 cm.
• adjacent regions to the north from Leysin via Gstaad, Adelboden, Lake Brienz, Hasliberg, Titlis, Schächental and along the Main Alpine Ridge from the Lukmanier Pass to Lower Engadine: 30 to 50 cm.
• as much as 10 to 30 cm in adjacent areas to the north, mostly dry in the far northeast

Temperature

At midday at 2000 m between -2 °C in the northwest, +2 °C in the south and +5 °C in the east

Wind

• Main Alpine Ridge, Upper Valais, eastern Bernese Oberland, central and eastern parts of the northern flank of the Alps, Grisons: strong southeasterly at high altitudes
• Central and northern Lower Valais, Vaud and Fribourg Alps, western Bernese Oberland: light to moderate southeasterly

Weather review for Wednesday

Precipitation became heavier in the south overnight to Wednesday, and then increasingly extended into the Bernese Oberland over the course of the day. The snowfall level was between 2200 and 2400 m on the central part of the southern flank of the Alps and between 2000 and 2200 m elsewhere. In the northeast, conditions were dry with sunny intervals.

Fresh snow

Snowfall above 2400 m from Tuesday to Wednesday afternoon:

• Mattmark, Simplon region, Binntal, southern Goms, Val Bedretto, Valle Maggia: 50 to 100 cm.
• rest of the Main Alpine Ridge from the Great St. Bernard to the San Bernardino Pass as well as the rest of Ticino, Lötschental, the Aletsch region and the rest of the Gotthard region: 30 to 50 cm.
• as much as 20 cm in adjacent areas to the north, mostly dry further north

Temperature

At midday at 2000 m between +1 °C in the northwest, +3 °C in the south and +7 °C in the east

Wind

• Strong to storm force south to southeasterly at high altitudes
• Strong foehn wind in the north overnight to Wednesday

Outlook

Temperatures will fall on Good Friday and there will be little precipitation. There will be sunny intervals in the west and still mostly cloudy conditions in the east. Winds will drop significantly. The risk of dry avalanches will decrease. However, the situation is likely to remain critical for snow sports participants. The risk of wet avalanches will also decrease, although moist and wet avalanches from the fresh snow are to be expected, especially in the west, with higher daytime temperatures and sunshine.

On Easter Saturday, conditions will be mainly overcast in the south, but there will be little precipitation. In the north, conditions will be mostly sunny and milder again. There will be light to moderate winds from southerly directions. Avalanche risk will decrease further and will be increasingly subject to daytime changes, especially in the north.