Swiss Avalanche Bulletin - 1st March 2012

SLF wrote:In the uppermost layers of the snowpack, the snow layering is unfavourable in some places of Lower Valais, on the northern flank of the Alps and in Grisons in particular. The snowpack has become thoroughly wet below about 2000 m, on north facing slopes below about 1600 m. At high altitudes the uppermost layers of the snowpack are moist on east to south to west facing slopes in particular.

In all regions of the Swiss Alps, the danger of wet snow avalanches tends to increase significantly through the solar radiation and the daytime warming cycle. On the northern flank of the Alps, in the Valais not including the regions of Saas Fee and the southern Simplon region, in northern and central Grisons and in the Engadine, the avalanche danger level will increase to Level 3 (considerable); in the remaining regions it will climb to Level 2 (moderate). Naturally triggered wet snow avalanches are possible on steep, east to south to west facing slopes below about 2600 m; on steep, north facing slopes, below about 1800 m. Wet snowslides can even occur at intermediate altitudes in the forest and on steep roadside embankments and can place sections of transportation routes at risk. Backcountry skiing and freeriding tours should be brought to a close early in the day.

In addition, below about 2600 m full depth snowslides can occur at any and all times. They can reach medium size and endanger exposed sections of transportation routes. Caution is urged below glide cracks in the snowpack.

Trend for Friday and Saturday

On Friday it will once again be sunny and very mild. On Saturday it will be only partly sunny and temperatures will gradually decline somewhat. The activity of wet snow and full depth avalanches will nonetheless remain high on Friday in particular. Wet snow avalanches are subject to a daytime warming cycle; full depth snowslides can be naturally triggered at any and all times.