obere Maggiatäler

Considerable avalanche danger will be encountered over a wide area.

As a consequence of a moderate to strong northerly wind, mostly small wind slabs formed at elevated altitudes. The avalanche prone locations are to be found in particular adjacent to ridgelines and in gullies and bowls. The fresh and older wind slabs are in some cases prone to triggering. They are to be evaluated with care and prudence in steep terrain.

Snowpack The fresh fallen snow of this week has been transported by strong-velocity winds from varying directions and snowdrift accumulations were generated over widespread areas which are prone to triggering. In the western regions these snowdrift accumulations are deep. In the eastern sector of the northern flank of the Alps and in Grisons, more than anywhere else, even old snow was transported from place to place. From region to region the snowdrift accumulations were subsquently blanketed by fresher snowfall and thereby made difficult to recognize. Some layers of the snowpack are expansively metamorphosed (faceted), particularly on north-facing slopes above 2200 m, and on south-facing slopes above approximately 2800 m. These weak layers are prone to triggering, particularly in the southern Valais and in Grisons, as stability tests and avalanche triggerings over the last few days have confirmed. Observed weather review Wednesday, 18.01.2023 In the northern regions skies were heavily overcast and there was snowfall registered over far-reaching areas falling as showers down to low lying zones. In the southern and the eastern regions it was partly sunny. Fresh snow Between Tuesday afternoon and Wednesday afternoon the following amounts of fresh snow were registered above 800 m:

• western Jura region, northern and furthermost western parts of the Lower Valais as well as the Vaud and Fribourg Alps: 15 to 30 cm, more from place to place;
• eastern Jura region, remaining parts of the northern flank of the Alps: 10 to 15 cm;
• in the other regions of Switzerland, less; or else it remained dry.

Overall in the period between Saturday afternoon, 14 January, and Wednesday afternoon, 18 January, the following amounts of fresh snow were registered above 2000 m:

• northern and furthermost western part of the Lower Valais: 70 to 100 cm; more from place to place on the French border;
• Vaud and Fribourg Alps: 50 to 70 cm;
• western Jura region, remaining parts of Lower Valais, western part of Bernese Alps: 25 to 50 cm;
• eastern Jura region, remaining parts of northern flank of the Alps and Upper Valais not including upper valleys of Visp and not including southern Simplon region 15 to 25 cm; in the other regions of Switzerland, less.

Temperature At 2000 m, between -10 °C in the northern regions and -8 °C in the southern regions. Wind

• Winds in the northern regions were blowing at moderate strength on Tuesday night, at light strength during the daytime hours on Wednesday, from westerly directions;
• winds in the southern regions initially slackened off during the daytime, then shifted to northwesterly directions.

Weather forecast through Thursday, 19.01.2023 In the northern regions the snowfall will come to an end on Wednesday night. During the daytime hours on Thursday it is expected to be rather sunny, still overcast in the eastern regions, accompanied by final snowfall. In the southern regions it will be rather sunny as a result of northerly foehn wind. Fresh snow Between Wednesday afternoon and Thursday morning, the following amounts of fresh snow are anticipated above 600 m:

• central and eastern sectors of the northern flank of the Alps: 5 to 15 cm;
• in the other regions of the west and of the north, only a few centimetres over widespread areas.

Temperature At 2000 m, -12 °C in the northern regions and -9 °C in the southern regions. Wind

• Winds in the northern regions will be blowing at light to moderate strength from westerly directions;
• winds in the southern regions will be blowing at moderate strength from northerly directions, intermittently strong-velocity northerly foehn wind will extend down into the valleys.

Outlook through Saturday, 21.01.2023 In the northern regions skies will be variably cloudy on both days, accompanied by bright intervals. Between Friday afternoon and Saturday evening, a small amount of snowfall is anticipated by Saturday evening. In the southern regions it will be rather sunny. As a result of moderate-strength northerly to northeasterly winds, blowing frequently at strong velocity at high altitudes, it will be extremely cold in the mountains. Avalanche danger level will incrementally decrease in the northern regions, in the southern regions the avalanche danger levels are not expected to change significantly.