untere Maggiatäler

Significant increase in avalanche danger as a consequence of new snow and stormy weather.

Snowpack

Through the impact of rainfall and subsequent drop in temperatures, deeply embedded layers inside the snow cover are generally compact and stable. At altitudes of approximately 2200 to 3000 m, icy crusts have formed over widespread areas due to the rainfall from last weekend, with the exception of in southern regions. In the vicinity of these crusts, expansively faceted weak layers have been observed in places. On the northern flank of the Alps, these layers are now blanketed over by small amounts of fresh fallen snow from this week. In the remaining regions of Switzerland, small-sized snowdrift accumulations lie atop the crusts. As a result of fresh snow and storm-strength winds, snowdrift accumulations will be generated which are prone to triggering. These drifts will be particularly wide-ranging in the major areas of precipitation on the northern flank of the Alps and in northern Grisons.

Weather forecast through Saturday, 25.11.2023

Snowfall down to low lying areas is anticipated over widespread areas, with the focal point in the northern Alpine Ridge and in northern Grisons. In the furthermost southern regions it will remain generally sunny.

Fresh snow

Between Friday evening and Saturday evening, the following amounts of fresh snow are anticipated above approximately 1500 m:

• northern Alpine Ridge from the Wildstrubel as far as Liechtenstein, Prättigau, Silvretta: 30 to 50 cm;
• remaining sectors of the northern flank of the Alps, Lower Valais not including furthermost western part of Lower Valais, remaining parts of Gotthard region, remaining parts of Grisons not including southern valleys of Grisons: 15 to 30 cm;
• in the other regions of Switzerland, 5 to 15 cm over widespread areas; in the furthermost southern regions it will remain dry.

Temperature

Temperatures will drop markedly. At midday at 2000 m, to -10 °C.

Wind

Winds in the mountains will be blowing at strong to storm strength from northerly directions.

Observed weather review Friday, 24.11.2023

In the northern regions, skies were predominantly overcast. In the inneralpine regions, cloud cover moved in during the course of the day. In the southern regions it remained still sunny for the most part.

Fresh snow

In the eastern regions there was a minor bit of snowfall above approximately 1400 m.

Temperature

At midday at 2000 m, between -2 °C in the northern regions and +5 °C in the southern regions.

Wind

Winds were blowing predominantly at strong velocity, intermittently at storm strength at high altitudes, from westerly to northerly directions.

Outlook through Monday, 27.11.2023Sunday

Throughout Saturday night the snowfall will continue down to low lying areas, the focal point on the northern Alpine Ridge and in northern Grisons. A strong to storm-strength northwesterly wind will be blowing. During the daytime hours on Sunday, bright intervals are anticipated in the western regions; it will be quite sunny in the Valais and in the Ticino. Winds are expected to slacken off, but only incrementally at altitudes of 3000 m. From the Haslital as far as Liechtenstein and in northern Grisons, an additional 15 to 30 cm of fresh snow is expected by Sunday evening. Avalanche danger levels will continue to increase in those regions, possibly reaching Danger Level 4 (high). Since there is still so little snow on the ground at intermediate altitudes, avalanches are not to be expected which reach down to low altitudes. In the remaining regions of Switzerland the avalanche situation for snow sports in outlying terrain away from secured ski pistes is critical over widespread areas. Fresh fallen snow and freshly generated snowdrift accumulations can easily be triggered as avalanches. Only in the furthermost southern regions will the avalanche situation not change significantly. However, there is hardly sufficient snow for winter sports in those regions.

Monday

Skies will be predominantely overcast, but it will remain dry to begin with. As the westerly to southwesterly winds intensify, snowfall down to low lying areas will set in during the course of the day. Avalanche danger levels are expected to decrease somewhat.