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.

Since Monday the wind has been strong. The clearly visible wind slabs of the last few days can be released 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. The danger of moist and wet avalanches will increase from midday.

Some snow fell on Monday in some regions. 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 will be good. The surface of the snowpack has frozen to form a strong crust and will soften during the day. At higher altitudes, snow cover becomes thinner and patchy; it is better at mid-altitudes, which are less exposed to the wind.

As a consequence of warming during the day and the solar radiation, the likelihood of dry and wet avalanches being released will increase a little on very steep slopes at elevated altitudes.