Wind slab
- Above 1,400 m
Snowpack
Tuesday’s and Wednesday’s fresh snow has been transported by the intermittently strong winds from westerly and northerly directions, resulting in widespread snowdrift accumulations. Especially on north-facing slopes, these are lying on a loose, faceted surface and some are prone to triggering. A little fresh snow will fall on Thursday resulting in further, mostly small snowdrift accumulations on the northern flank of the Alps.
In southern Valais, Ticino and Grisons, the snowpack contains many soft layers of faceted crystals and is therefore weak. Snowpack structure is most unfavourable in the Engadine and the neighbouring southern valleys of Grisons.
The gliding snow activity has decreased significantly with the lower temperatures.
Weather forecast to Thursday
Conditions will be cloudy in the north. In the Jura and on the northern flank of the Alps, precipitation will fall intermittently from midnight, as snow above 800 m. There will be sunny intervals in the inneralpine regions, and the south will be sunny.
Fresh snow
From Wednesday evening to Thursday afternoon, the following amounts will fall above 1200 m:
Temperature
At midday at 2000 m, between -6 °C in the north and -2 °C in the south.
Wind
In the north
In the south
Weather review for Wednesday
Conditions were very cloudy with intermittent precipitation. The snowfall level dropped to low altitudes overnight. Brighter conditions developed over the course of the day in Valais and Ticino.
Fresh snow
Between the onset of precipitation on Tuesday morning and Wednesday afternoon, the following amounts fell above approximately 1600 m:
Temperature
At midday at 2000 m, between -5 °C in the north and -2 °C in the south.
Wind
In the north
In the south
Outlook
Friday and Saturday will be mostly sunny in the mountains. In the north, the wind will be light to moderate, initially from westerly directions, then from the northeast. In the south, there will be light winds from westerly directions. There will be a moderate Bise wind in the Jura on Saturday. The zero-degree level will be around 1000 m in the north and around 1400 m in the south.
The danger of dry avalanches will decrease slightly.
Bulletin data: WSL Institute for Snow and Avalanche Research SLF (CC BY 4.0)