Iffigen

Moderate avalanche danger will be encountered over a wide area. Fresh wind slabs require caution

Moderate avalanche danger will be encountered over a wide area. Fresh wind slabs require caution

Danger level 2 (moderate) will be reached in the course of the day. As a consequence of new snow and a strong to storm force northerly wind, avalanche prone wind slabs will form. These are to be found in particular in gullies and bowls, and behind abrupt changes in the terrain. Avalanches can be released by a single winter sport participant, but they will be small in most cases. Ski touring and other off-piste activities, including snowshoe hiking, call for careful route selection.

As a consequence of the new snow and winds, snowdrift accumulations will be freshly generated. They will be deposited on west-facing, north-facing and east-facing slopes, frequently on top of a loose, expansively metamorphosed (faceted) surface layer of snow. Particularly on these slopes, the freshly generated snowdrift accumulations are prone to triggering. At the present time they constitute the main danger. At lower altitudes the snowpack layering on the northern flank of the Alps and in the western part of Lower Valais is favourable over widespread areas. On top of or beneath the rain crust which formed at the end of December there are weak layers evident; nonetheless these layers are not very prone to triggering. From the central part of Valais over the northern part of Ticino as far as Grisons there are weak layers evident deeper down inside the snowpack. However there have hardly been any avalanche triggerings reported in these deeply embedded layers of the old snowpack for a longer period of time.

Following a night of clear skies, it was sunny. Fresh snow: - Temperature: At midday at 2000 m, +1 °C. Temperatures dropped during the afternoon, from the west. Wind: Winds were blowing predominantly at light strength, intermittently at moderate strength in the northern regions, at stronger velocity in the Jura region, from southwesterly directions. On Wednesday night, cloud cover is expected to move in swiftly and snowfall will set in, falling down to low lying areas. During the daytime on Thursday, skies will be heavily overcast in the northern regions and snowfall is expected down to low lying areas. During the afternoon in the western and the southern regions, it is expected to become increasingly sunny. Fresh snow: By Thursday afternoon, the following amounts of fresh snow are anticipated: - furthermost eastern part of the Bernese Alps, central and eastern sectors of the northern flank of the Alps, northern Grisons: 10 to 20 cm; - Jura region as well as the remaining regions of the Alps: 5 to 10 cm; on the southern flank of the Alps it will remain predominantly dry. Temperature: At midday at 2000 m: -8 °C in the northern regions and -5 °C in the southern regions. Wind: - Winds will be northerly, blowing at strong velocity particularly at high altitudes, during the afternoon intensifying to storm strength; - in the Ticino, strong-velocity northerly winds will extend down to the valleys.

On Friday and on Saturday in the northern and the eastern regions, a small amount of additional snowfall is anticipated. In the southern and the western regions it will remain dry. Temperatures will persist at low levels and the northerly wind will still be blowing at strong velocity on Friday in particular. The avalanche danger levels in northern and eastern regions are expected to increase slightly, in the other regions of Switzerland avalanche danger will not change significantly.