Tennen Mountains, Gosaukamm

Loss of firmness due to solar radiation

Loss of firmness due to solar radiation

Avalanche danger above 2000m is MODERATE, below that altitude danger is LOW and rises to MODERATE during the day. On sun-drenched steep slopes, naturally or skier-caused small-to-medium loose-snow avalanches are possible. Also glide-snow avalanches (medium-to-large) are possible on steep grass-covered slopes. At high altitudes there are danger zones due to fresh snowdrifts behind protruberances and in gullies, increasingly in NW to N to SE facing slopes, where even low additional loading can trigger a small slab. Very few danger zones exist in the shallow-snow transitions (persistent weak layer). There, large additional loading can trigger a slab avalanche which can reach medium size.

At low and intermediate altitudes the moist snowpack is shallowly/breakably encrusted. During the daytime it turns to firn snow, depending on gradient and aspect. On steep sunny slopes the snowpack loses its firmness. On very steep grassy slopes the snowpack can glide away over the ground. At high altitudes lies 10-20 cm of melt-freeze encrusted snow, on shady slopes atop faceted old snow which is often poorly bonded. Beneath the superficial melt-freeze crusts are soft, faceted crystals (persistent weak layer) which are unlikely to trigger for the moment.

On Saturday following a night of frequently clear skies, sunshine until afternoon; thereafter convective cloud will make itself noticeable, the peaks can temporarily disappear in fog. At 2000 m: -5 to -3 degrees; at 3000 m: -9 degrees. The SE winds can reach 40 km/hr. On Saturday night, clear skies. But southerly foehn wind will hamper the cooling. During the daytime on Sunday, sunshine will often be unimpaired, amid strong southerly winds (40-60 km/hr). At 2000 m: -6 to -3 degrees; at 3000 m: -9 degrees.

On Sunday in the foehn-influenced regions, swift loss of firmness and the naturally triggered avalanches will be launched early in the day. Freshly generated snowdrifts from the foehn wind. Where there is no wind, the melt-freeze crust will transform to firn snow.