Wind slab
- Above 2,800 m
Increase in avalanche danger at elevated altitudes.
Snowpack
Following the rounds of snowfall during October, there is currently a multi-layered, but frequently still thin snowpack on the ground in high alpine regions, atop the glaciers and in north-facing gullies and bowls above approximately 2800 m. In the Bernina region at high alpine altitudes there is already a thick snow cover. High altitude locations were covered with snow at the beginning of this week, and there is 10 to 30 cm of snow on the ground over the flat fields where measurements are registered. The snowpack surface shows severe effects from wind impact. On wind-protected north-facing slopes, the fresh fallen snow from Tuesday is still loosely packed in some places, thereby forming a relatively unfavourable base for the next round of fresh snow which is anticipated. As a consequence of southwesterly winds, the fresh fallen snow on Thursday will be transported and avalanche prone snowdrift accumulations are expected to be generated at high altitudes.
Weather forecast through Thursday, 02.11.2023
In the southern and the western regions, a small amount of precipitation is anticipated on Wednesday night which will intensify on Thursday during the course of the day. In the eastern regions and in the central Valais there will be foehn-induced bright intervals during the morning hours, precipitation will also set in there during the course of the day. The snowfall level in southern regions will lie at 1800 to 2000 m, in the Engadine at 2200 m for a brief spell. In the northern regions the snowfall level will descend from 2200 m down to approximately 1600 m.
Fresh snow
Between Wednesday evening and Thursday afternoon above approximately 2500 m:
Temperature
Temperatures are expected to drop: at midday at 2000 m to between +1 °C in the western regions and +4 °C in the eastern regions.
Wind
Observed weather review Wednesday, 01.11.2023
Following a night of predominantly clear skies, it was predominantly overcast on Wednesday accompanied by foehn-induced bright intervals in the northern regions. In the southern regions there were showers during the afternoon, a few centimetres of snowfall from place to place above approximately 2000 m.
Fresh snow
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Temperature
At midday at 2000 m, +4 °C in the northern regions and +2 °C in the southern regions.
Wind
Winds were blowing at light to moderate strength, to some extent at strong velocity on the northern Alpine Ridge, from southerly to southwesterly directions.
Outlook through Saturday, 04.11.2023
By Friday morning, precipitation over widespread areas is anticipated. The snowfall level is expected to descend down to approximately 1000 m. During the course of the day on Friday, conditions will be variable in the northern regions accompanied by snow showers extending down to intermediate altitudes. In the southern regions it will be partly sunny as a result of northerly winds. On Saturday, precipitation is anticipated particularly in the western regions; and the snowfall level will ascend from 1200 m up to approximately 2000 m. Avalanche danger levels will increase on Thursday night over widespread areas, thereafter the danger will incrementally decrease. On Saturday, avalanche danger could increase again to a small extent in the western regions.
Bulletin data: WSL Institute for Snow and Avalanche Research SLF (CC BY 4.0)