Pays d'Enhaut

Considerable danger of wet avalanches will be encountered over a wide area.

The surface of the snowpack will cool hardly at all during the overcast night. As a consequence of the rain at any time wet and gliding avalanches are to be expected below approximately 2400 m. These can reach large size in isolated cases in particular on north facing slopes. As a consequence of warming during the day and solar radiation more frequent wet avalanches are to be expected as the day progresses. This applies in all aspects below approximately 2800 m.

Fresh and older wind slabs are in some cases prone to triggering. This applies in particular on north and east facing slopes above approximately 2400 m. The wind slabs are to be evaluated with care and prudence in steep terrain.

Snowpack Fresh fallen snow and freshly generated snowdrift accumulations from Thursday and Friday were deposited on north-facing slopes above approximately 2600 m on top of a loosely-packed old snowpack surface, in Grisons on top of surface hoar. Particularly there, but also in high alpine regions in general, these layers are still prone to triggering. Furthermore, on west-facing, north-facing and east-facing slopes above approximately 2400 m, there are layers which are deeply embedded inside the snow cover that are weak. Numerous avalanche releases on north-facing slopes on Friday, some of which were large-sized avalanches, demonstrated that fractures deep down inside the snowpack are possible, particularly in the inneralpine regions of Grisons. The same thing cannot be excluded in the southern Valais and on the southern flank of the Alps. As a consequence of the rainfall as well as the mild, relatively moist air, wet-snow avalanches can be expected on north-facing slopes more than anywhere else, im some places even during the nocturnal hours. On the northern flank of the Alps and in the northern Valais, gliding avalanches are possible Observed weather review Saturday, 22.04.2023 Following a night of partly clear skies, during the daytime hours skies were overcast in the western regions, in the other regions of Switzerland it remained quite sunny for longer. In the western regions there were isolated showers registered during the morning hours, not until afternoon in the other regions of Switzerland. Fresh snow In the western regions above 2500 m, a few centimetres of fresh snow was registered from region to region, below that altitude a small amount of rain. Temperature At midday at 2000 m, between +7 °C in the northern regions and +3 °C in the southern regions. Wind

• Winds during the nighttime hours were blowing at moderate strength, from place to place on the northern Alpine Ridge at strong velocity, from southerly directions;
• during the daytime, winds were blowing at light to moderate strength from southwesterly directions.

Weather forecast through Sunday, 23.04.2023 Nocturnal skies will be overcast and a small amount of precipitation is anticipated in the northern regions more than anywhere else. During the daytime hours in the northern regions, it will temporarily become quite sunny from the west, subsequently skies will again become overcast accompanied by isolated showers. In the southern regions, skies will remain overcast also during the daytime and a small amount of precipitation is expected. Fresh snow The snowfall level lies at approximately 2200 m. Above 2500 m the following amounts of fresh snow are anticipated by Sunday afternoon:

• from the Trient region into the Vaud Alps: 10 to 20 cm;
• in the other regions of Switzerland, mostly less than 10 cm; in the Lower Engadine it is expected to remain dry.

Temperature At midday at 2000 m, +5 °C in the northern regions and +2 °C in the southern regions. Wind Winds will be blowing at moderate strength, during the afternoon at strong velocity at elevated altitudes and also in some places in the eastern foehn-impacted regions, from southwesterly directions. Outlook through Tuesday, 25.04.2023 Monday Skies will frequently be overcast and some precipitation is anticipated during the nighttime hours in particular. The snowfall level will descend down to approximately 1500 m. At heightened altitudes, approximatealy 10 to 20 cm of fresh snow is expected to fall over widespread areas, however the amounts of snowfall could vary greatly from place to place. Particularly at elevated altitudes, winds will be blowing at strong velocity and shift from southwesterly to westerly. In the furthermost southern regions it will remain rather sunny during the daytime as a result of northwesterly winds. The danger of dry-snow avalanches is expected to increase slightly over widespread areas. The danger of wet-snow avalanches will diminish. Tuesday On Tuesday in the northern regions, skies will be heavily overcast accompanied by precipitation which will fall as snow above approximately 1200 m. On the northern flank of the Alps, approximately 20 to 30 cm of fresh snow is expected, but these forecasted amounts are still uncertain. In the furthermost southern regions it will be predominantly sunny as a result of strong-velocity northerly winds. The danger of dry-snow avalanches is expected to increase significantly in the northern regions, in the southern regions avalanche danger levels are not expected to change significantly. Wet-snow avalanches can be expected only in isolated cases.