Bollettino valanghe

Isolated danger zones at high altitudes

Isolated danger zones at high altitudes

Weak layers in the uppermost part of the snowpack can in isolated cases be triggered by one sole skier. Such danger zones occur esp. on steep N/W/E-facing slopes above 2100m. Avalanches can in isolated cases grow to medium size. Due to solar radiation and daytime warmth, increasingly frequent wet-snow avalanches can be expected, especially on extremely steep sunny slopes, likelihood of triggering increases, releases mostly small-sized since many starting zones have discharged. Acute danger of falling on hardened snowpack surfaces in steep terrain, esp. in the morning hours.

Nocturnal outgoing longwave radiation will be quite good. The snowpack surface will freeze and be capable of bearing loads in early morning, softening subsequently over the course of the day. The old snowpack is moist, particularly on sunny slopes at all altitudes and on shady slopes below 2100m. Inside the old snowpack on N/W/E-facing slopes there are faceted, expansively metamorphosed weak layers, esp. abov 2200m. Below 1500m there is hardly any snow on the ground.

On Thursday a variety of clouds and sunshine, the highest summmits will often disappear in the convective clouds and fog. In exposed terrain, a strong NW wind will be blowing, gusts reaching 70 km/hr. At 1000m: 11 degrees; 2000m: +1 degree. Source: GeoSource Austria

Increase in avalanche danger levels due to higher daytime temperatures and solar radiation