östliche Berner Voralpen

Snowpack

There has been considerable snowfall in the west and south over the last 3 days, with very heavy falls in the west overnight to Thursday. With sometimes strong southeasterly winds, large snowdrift accumulations have formed at high altitudes. In those regions most exposed to precipitation, there have been numerous naturally triggered avalanches, some very large and advancing down into the valleys. Naturally triggered avalanches are still possible in these regions, especially overnight to Friday. These may start in the old snowpack, especially in high-altitude, shady slope catchment areas, and may become very large and advance down into the valleys. In the inneralpine regions of Grisons, where there has been only little fresh snow, weak layers in the old snowpack are still sometimes prone to triggering.

The old snowpack is water-saturated on southern slopes in the high Alpine regions and on eastern and western slopes up to around 2800 m. On northern slopes, most of the old snowpack is water-saturated up to around 2400 m. At intermediate altitudes, the fresh snow fell widely on snowless ground. Gliding and wet avalanches are still to be expected and may become large in those regions most exposed to precipitation.

Weather forecast to Friday

Precipitation will come to an end in the west during the night. On Friday, conditions will be cloudy at first and increasingly sunny from the west as the day progresses. In the east there will still be a little precipitation until midday with conditions becoming brighter in the afternoon. The snowfall level during the night will be between 1200 and 1400 m in the north and between 1600 and 1800 m in the south. During the day, it will rise to around 1800 m in the northeast.

Fresh snow

Snowfall from Thursday to Friday afternoon above around 1800 m:

• southern Upper Valais, central and eastern parts of the northern flank of the Alps, Grisons, southern flank of the Alps: 5 to 15 cm.
• elsewhere: up to 5 cm.

Temperature

At midday at 2000 m around 0 °C in the west, -2 °C in the northeast and +2 °C in the south

Wind

Light to moderate, in the high Alpine regions moderate westerly

Weather review for Thursday

Snow fell heavily to form deep accumulations In Valais and on the western part of the northern flank of the Alps. Snowfall subsided from midday. The snowfall level dropped to between 1000 and 1300 m during the night in the west and in some cases down to low altitudes in the Rhone Valley and the Bernese Oberland. In the south, it dropped to around 1900 m and, in the east, was 1500 to 2000 m. In the northeast, conditions were changeable with some snowfall during the day.

Fresh snow

Snowfall from Wednesday to Thursday afternoon, in the west above around 1400 m and in the south above around 2400 m:

• southern Valais, western Ticino, also Northern Alpine Ridge from Montana to the Aletsch region: 80 to 120 cm, in the Simplon region up to 150 cm
• rest of Valais, rest of the Northern Alpine Ridge from the Trento region to the Grimsel Pass: 60 to 80 cm.
• adjacent regions to the north from the Chablais to the eastern Bernese Alps: 40 to 60 cm, as much as 20 to 40 cm in the western Prealps
• Main Alpine Ridge from the Urseren to the Bernina region: 15 to 30 cm.
• elsewhere less or dry

Total snowfall from Tuesday to Thursday afternoon, in the west above around 2000 m and in the south above around 2600 m:

• southern Upper Valais except for Obergoms, also western Ticino: 120 to 180 cm.
• southern Lower Valais, Obergoms, northern Lower Valais from Montana to the Aletsch region: 80 to 120 cm, and 60 to 80 cm in adjacent regions to the north
• as much as 20 to 40 cm in the western Prealps, 20 cm on the Jura highlands
• central part of the northern flank of the Alps, Main Alpine Ridge from the Urseren to Val Müstair: 20 to 40 cm.

Temperature

At midday at 2000 m around -2 °C in the west, +4 °C in the east and +2 °C in the south

Wind

Moderate, sometimes strong at high altitudes from southeast to east

Outlook

On Saturday, conditions will be mostly cloudy in the south, but there will be little precipitation. The snowfall level will be around 2000 m. In the north, conditions will be mostly sunny and milder again. The southerly wind will be light to moderate, rising to strong in the afternoon. Fresh snowdrift accumulations will be prone to triggering. The risk of naturally triggered dry avalanches will decrease significantly. The risk of wet and gliding avalanches will be subject to daytime changes, especially in the north.

On Sunday, there will be sunny intervals in the north while there will be heavy cloud with precipitation in the south. The snowfall level will be around 2000 m. On the Main Alpine Ridge in Valais and in Ticino, 20 to 30 cm of snow is expected at high altitudes. There will be a moderate to strong southerly wind. Avalanche risk may increase somewhat in the south but will otherwise remain largely unchanged.