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 NE to E to S 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 softens, 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 there is 10-20 cm of fresh snow deposited atop a melt-freeze encrusted surface, on shady slopes atop faceted crystals where there is often unfavorable bonding. Inside the compact old snowpack there are faceted, soft layers (persistent weak layer) but these are currently unlikely to trigger.

Thursday night will be heavily overcast, but dry. On Friday, heavy clouds will often impede the sun, but bring no precipitation (higher peaks in fog). As of midday, more sunshine, although impaired due to Sahara dust. Moderate N/NE winds. At 2000 m: -2 to +1 degree, at 3000m: -9 degrees. On Saturday, frequent sunshine til midday following frequently clear nights. In the afternoon, convective cloud build-up in some places, possibly cloaking the summits in fog. At 2000m: -3 to -1 degree; at 3000 m, -9 degrees.

On Saturday, daytime avalanche danger cycle. The melt-freeze will transform to firn.