südliches Urseren

Considerable avalanche danger will be encountered over a wide area.

The large quantity of fresh snow of the last few days and the sometimes large wind slabs are lying on top of a weakly bonded old snowpack. Single winter sport participants can release avalanches easily. These can release the weakly bonded old snow as well and reach large size in some cases. Additionally avalanches can also be released in deep layers. Whumpfing sounds can indicate the danger. Backcountry touring and other off-piste activities call for experience in the assessment of avalanche danger and caution.

Below approximately 2500 m small and medium-sized gliding avalanches are possible. Areas with glide cracks are to be avoided as far as possible.

Snowpack The immense amounts of fresh fallen snow in the western and in the northern regions over the course of the last few day are settling and consolidating. They have been deposited on top of soft layers consisting of faceted crystals over widespread areas above approximately 2200 m. Fractures in these deeply embedded layers of snow continue to be possible. This applies particularly to the inneralpine regions of the Valais and Grisons, where the snowdrift accumulations are blanketed with shallower layers of fresh snow. In addition, the fresh fallen snow has been intensively transported by strong to storm-strength westerly winds. Far-reaching snowdrift accumulations have thereby been generated, including to zones far distant from ridgelines. The fresh fnow and fresh snowdrifts tend to increase significantly in size and spread with ascending altitude. As a consequence of the mild temperatures, the snow cover has become superficially moistened up to approximately 2700 m. Below 2200 m, the snowpack has become thoroughly wet as a result of the rainfall in the regions of precipitation. Gliding avalanches continue to be possible in those areas more than anywhere else. Observed weather review Sunday, 25.12.2022 Christmas Day was sunny and mild. The zero-degree level ascended to over 3000 m. Fresh snow - Temperature At midday at 2000 m, between +7 °C in the northern regions and +2 °C in the southern regions. Wind Winds were blowing at moderate to strong velocity from westerly directions. Weather forecast through Monday, 26.12.2022 Nocturnal skies on Sunday night will be clear. During the daytime hours on Monday it will be sunny to start with in some places. During the course of the day cloud cover will increase from the northwest and, in northern regions as the afternoon unfolds, precipitation will set in. The snowfall level will descend from approximately 2000 m down towards 1600 m by evening. In the southern regions it is expected to remain dry and rather sunny. Fresh snow Between Monday midday and Monday evening on the northern Alpine Ridge, 5 to 10 cm of fresh snow is anticipated. Temperature In the northern regions, temperatures are expected to drop significantly, at midday at 2000 m to approximately +1 °C. Wind Winds will be blowing at moderate to strong velocity, at storm strength in some places in the high alpine regions, from westerly directions. Outlook through Wednesday, 28.12.2022 Tuesday During the nocturnal hours on Monday night the snowfall level will continue to descend further, down to 1400 m in the western regions, down to 1200 m in the eastern regions. In the central and eastern sectors of the northern flank of the Alps, approximately 10 to 20 cm of fresh snow is anticipated, less in the other regions of Switzerland. On Tuesday morning this period of precipitation will come to an end and it will become rather sunny. Winds will be strong to begin with, later on slackening off, from the west. As a consequence of the fresh fallen snow and the strong-velocity westerly winds, fresh snowdrift accumulations can be generated from place to place. The avalanche danger levels are not expected to change significantly. Wednesday In early morning it will be predominantly sunny. During the afternoon to an increasing extent, cloud cover will move in from the west. Winds will be blowing at moderate to strong velocity from the west. Avalanche danger levels are expected to gradually decrease.