untere Maggiatäler

In the west a high avalanche danger will be encountered over a wide area.

The fresh and older wind slabs represent the main danger. They are only small but in some cases prone to triggering. Even a small avalanche can sweep snow sport participants along and give rise to falls.

Avalanche bulletin survey: intermediate levels - helpful or confusing? Link to the survey in AvaBlog (on SLF-App WhiteRisk or at slf.ch)

Snowpack As a consequence of furthern snowfall and strong-velocity westerly winds, both size and frequency of snowdrift accumulations continue to increase in the western and the northern regions. Fresh fallen snow and freshly generated snowdrift accumulations lie deposited on shady slopes on top of an unfavourable old snowpack surface widespread. Avalanches can easily be triggered in those places or, in the major areas of precipitation, continue to trigger naturally. On sunny slopes the old snowpack surface was more favourable prior to the snowfall. On the northern flank of the Alps on north-facing slopes, furthermore, there are expansively metamorphosed (faceted) layers deeply embedded inside the snow cover in some places. In the southern Valais and in the Grisons the entire old snow cover is expansively metamorphosed (faceted) and loosely-packed widespread on north-facing slopes. In the southern Valais more than anywhere else, avalanches can fracture deep down to lower layers inside the snowpack. In the western regions, moist avalanches are expected to trigger from the fresh fallen snow on steep sunny slopes as a consequence of higher temperatures and solar radiation. Observed weather review Saturday, 11.03.2023 In the northern regions there was precipitation over far-reaching areas. The snowfall level generally lay between 1600 and 1000 m, in the eastern regions the snowfall level descended intermittently down to low lying areas. In the southern regions it was partly sunny in the afternoon. Fresh snow Between Friday afternoon and Saturday afternoon the following amounts of fresh snow were registered above 1800 m:

• Valais, northern Alpine Ridge, Gotthard region: mostly 30 to 50 cm; up to 70 cm in the Aletsch region;
• remaining parts of the northern flank of the Alps, Northern Grisons and the western part of Central Grisons: 15 to 30 cm;
• in the other regions of Switzerland, 5 to 15 cm over far-reaching areas; in the southern regions it remained dry.

Thus, the following overall amounts of fresh snow have been registered above approximately 2200 m since the beginning of this period of precipitation on Tuesday evening:

• furthermost western part of Lower Valais: 100 to 130 cm;
• remaining parts of Valais: 60 to 100 cm;
• remaining parts of the northern Alpine Ridge and Gotthard region: 30 to 60 cm;
• remaining parts of the northern flank of the Alps and northern Grisons: 15 to 30 cm;
• in the remaining parts of Switzerland, less.

Temperature At midday at 2000 m, between +2 °C in the southwestern regions and -4 °C in the northeastern regions. Wind Winds in the northern regions

• were blowing at strong velocity at elevated altitudes, intermittently at storm strength, from westerly directions;
• in the remaining northern regions blowing predominantly at moderate strength;

in the southern regions

• winds were blowing at moderate to strong velocity from northwesterly directions.

Weather forecast through Sunday, 12.03.2023 During the nocturnal hours on Saturday and on Sunday morning, precipitation is anticipated over widespread areas. During the daytime hours on Sunday skies will be heavily overcast for the most part. In the western regions it is expected to be dry as of the midday hours, accompanied by bright intervals; in the northeastern regions a small amount of snowfall is expected also during the afternoon. The snowfall level will lie betweeen 1200 and 1500 m. In the southern regions it will be quite sunny. Fresh snow Between Saturday afternoon and Sunday afternoon, the following amounts of fresh snow are anticipated above 1800 m:

• Valais not including the Simplon region, northern Alpine Ridge west of the Linth: 20 to 30 cm; more from place to place;
• Simplon region, remaining parts of the northern flank of the Alps and northern Grisons: 10 to 20 cm;
• in the remaining regions of Switzerland, only a few centimetres; in the southern regions it is expected to remain dry.

Temperature Temperatures are expected to rise. At midday at 2000 m, between -2 °C in the northern regions and 0 °C in the southern regions. Wind Winds in the northern regions

• will be blowing from northwesterly directions at strong velocity at elevated altitudes;
• otherwise winds will be blowing at moderate to strong velocity from westerly directions;

in the southern regions

• winds will be blowing from northwesterly directions at strong velocity at elevated altitudes;
• otherwise in the southern regions, winds will be blowing predominantly at moderate strength from northwesterly directions.

Outlook through Tuesday, 14.03.2023 Monday Following a night of partially clear skies it will be quite sunny during the daytime hours. Temperatures are expected to rise noticeably, the zero-degree level will ascend to nearly 3000 m. Winds in the northern regions will be blowing at strong velocity, even reaching storm strength in the afternoon hours, and increasingly as foehn wind. In the southern regions, winds will be blowing predominantly at moderate strength from westerly directions. The danger of dry-snow avalanches will decrease somewhat in the western and the northern regions, nevertheless the situation will remain treacherous for winter sports enthusiasts in open terrain apart from secured ski runs. As a consequence of higher temperatures and solar radiation, moist avalanches can be expected to release from the fresh fallen snow on sunny slopes. In the southern regions the avalanche situation is more favourable. Tuesday On Monday night precipitation is expected to set in from the west. During the daytime hours on Tuesday, skies will be overcast and precipitation is anticipated over widespread areas. The snowfall level will descend from 1800 m down to approximately 1000 m. In the furthermost western part of Lower Valais, approximately 50 cm of fresh snow is expected; in the other regions, 15 to 25 cm widespread. At elevated altitudes a strong, in some places a storm-strength wind will be blowing from westerly to northwesterly directions. In the southern regions it will be partly sunny during the afternoon. The danger of dry-snow avalanches is expected to increase once again in the major areas of precipitation.