nördliches Urseren

Outside marked and open pistes a precarious avalanche situation will be encountered over a wide area.

Snowpack

The large amounts of new snow in the north from last weekend are gradually consolidating. The new fallen snow from Tuesday has been transported by strong winds. Where the new fallen snow fell at altitude on old snowpack eroded irregularly by the wind, the bonding is quite favourable. On wind-protected slopes, the snow near the surface was still quite loose in many places, and fresh snow and freshly generated snowdrift accumulations are particularly prone to triggering in these places. There are crusts in the centre of the snowpack due to repeated rainfall and the subsequent falling temperatures. These are mostly compact and stable, but some weaker layers are also embedded there.

Weather forecast through Wednesday, 29.11.2023

During Tuesday night, a little snow will fall to low altitudes. This will clear away during the second half of the night. During the day it will be mostly sunny, with clouds gathering in the afternoon in the west.

Fresh snow

During Tuesday night, the following amounts of fresh snow are anticipated above approximately 800 m:

• eastern Bernese Oberland, central and eastern parts of the northern flank of the Alps, northern Grisons: 5 to 10 cm, with locally up to 15 cm on the eastern part of the northern flank of the Alps;
• elsewhere a few centimetres, dry in the south.

Temperature

At midday at 2000 m, between -4 °C in the west and -8 °C in the east.

Wind

• During Tuesday night, winds will be blowing at moderate to strong strength from the north.
• During the daytime hours, they will turn to the west and blow at weak to moderate strength, freshening up again in the afternoon.

Observed weather review Tuesday, 28.11.2023

It was very cloudy and there was widespread precipitation, centred in the west and north. The snowfall level dropped from 1200 m to around 600 m. It remained dry in the far south and was mostly sunny.

Fresh snow

From Monday evening to Tuesday afternoon, above approximately 1200 m:

• extreme west of Lower Valais, northern Alpine Ridge: 40 to 60 cm;
• other parts of the northern flank of the Alps and Valais, northern Prättigau, Jura: 20 to 40 cm;
• other parts of northern Grisons and the Gotthard region, northern Lower Engadine: 10 to 20 cm;
• in the remaining regions of Switzerland, less.

Temperature

At midday at 2000 m, -6 °C in the north and -4 °C in the south.

Wind

Winds turning from southwest to northwest

• moderate to strong in the north, partly stormy on the Jura heights and in the afternoon in Grisons;
• weak to moderate in the south.

Outlook through Friday, 01.12.2023

It will be very cloudy with widespread precipitation centred in the west. During Wednesday night, the snowfall level will rise, reaching around 2000 m in the west. In the course of Thursday it will drop to around 1600 m, and on Friday to 1000 m. In the westernmost and northern Valais, 40 to 70 cm of snow is expected to fall at high altitudes, and up to 90 cm on the border with France. There will be little precipitation in the far south and in the inneralpine regions of Grisons. The southwesterly wind will blow strongly at high altitudes and at storm force at times during Wednesday night. It will subside on Friday. The avalanche danger will increase widely on Thursday, and significantly so in the west and north. Naturally triggered avalanches are to be expected. In the extreme west of Lower Valais, danger level 4 (high) is probable. More large and occasionally very large naturally triggered avalanches are expected here. In other parts of the Lower Valais and northern Valais, danger level 4 could be reached. In addition, wet snow and gliding avalanches will increasingly be triggered by the rain below 2000 m. As Friday progresses, the avalanche danger will gradually decrease, especially as far as naturally triggered avalanches are concerned. The situation will remain critical for snow sports away from the open pistes.