Bregenzerwald Mountains

Swiftly rising daytime avalanche danger. Near-surface weak layers can often be triggered by winter sports enthusiasts.

Swiftly rising daytime avalanche danger. Near-surface weak layers can often be triggered by winter sports enthusiasts.

Following a night of clear skies, generally favorable backcountry touring conditions in early morning. However, avalanche danger, particularly on very steep north-facing slopes, increases rapidly at 1800-2200m due to solar radiation and daytime warming in all aspects, particularly below 2400m, also above that altitude on very steep sun-exposed slopes. Naturally triggered avalanches can be expected; persons can trigger wet-snow slab avalanches. If near-surface avalanches fracture down to deeper layers of the snowpack they can, in isolated cases, grow to large size. In addition, winter sports enthusiasts can trigger near-surface weak layers on high-altitude shady slopes. Danger zone are impossible to recognize. Attention: danger of taking a fall on hardened snowpack surfaces on steep slopes.

Good nocturnal outgoing longwave radiation will generate a gradually thicker melt-freeze crust which, however, will swiftly soften up during the course of the day. At altitudes between 1800 and 2200m the snowpack (also on north-facing slopes) is thoroughly wet and the ground-level rotten snow is extremely prone to triggering already in early morning. On high-altitude shady steep slopes there are unfavorable intermediate layers in the uppermost metre of the snowpack which in places can be triggered. A solid mid-section of compact layers inside the snowpack blankets a fundament of buried hoar and faceted crystals.

On Thursday, no longer brilliant sunshine, but good mountain weather. It will remain dry, quite sunny and mild. During the course of the day, high-altitude clouds will move in high above the summits. They will hamper the sunlight, bring about diffuse light conditions. Temperature at 2000m: 6 degrees; at 3000m: -1 degree. Brisk northwesterly winds at high altitudes.

Due to reduced nocturnal longwave outgoing radiation on Thursday night, wet-snow problem will predominate already in early morning on Friday.