Border Graie Alps

Wind slabs and weakly bonded old snow represent the main danger.

Wind slabs and weakly bonded old snow represent the main danger.

Some snow has fallen since Sunday in some regions. Since Monday the wind has been strong. The clearly visible wind slabs of the last few days can be released by a single winter sport participant in some cases at intermediate and high altitudes, especially at their margins. Places where persistent weak layers exist in the old snowpack, sometimes consisting of buried surface hoar, are unfavourable. Especially on steep west, north and east facing slopes the avalanches can be triggered in the weakly bonded old snow and reach medium size. This applies in particular in case of a large load.

In some regions 5 to 20 cm of snow has fallen since Sunday above approximately 1700 m. As a consequence of a strong northwesterly wind, hard wind slabs formed since Monday in particular in areas not adjacent to ridgelines. Individual weak layers exist in the centre of the snowpack at intermediate and high altitudes. Outgoing longwave radiation during the night was good. The surface of the snowpack has frozen to form a strong crust and will soften during the day, in particular on sunny slopes at low and intermediate altitudes. Adjacent to ridgelines at high altitude snow depths vary greatly, depending on the infuence of the wind. Below the wind-eroded peaks, above around 1600 m, more snow is lying for the time of year.