Stub and Gleinalpe

Beware trigger-sensitive snowdrifts

Beware trigger-sensitive snowdrifts

Above the treeline avalanche danger is moderate. Danger zones are from trigger-sensitive snowdrift accumulations, esp, in extended S/E facing terrain. At entries to gullies and bowls and behind protruberances, slab avalanches can be triggered by 1 person. Danger zones increase with ascending altitude. The gliding snow problem is receding. On very steep grass-covered slopes or smooth rocks, isolated glide-snow avalanches can release in all aspects.

The fresh snow from Wednesday and Thursday (up to 30 cm) has been transported by strong winds, generating snowdrift accumulations which are prone to triggering, deposited atop a melt-freeze encrusted snowpack surface. Weak layers lurk inside the snowdrifts and soft layers in the form of faceted crystals, esp. in transitions to the old snow. At intermediate altitudes the drifts are better bonded with the old snowpack. The snowpack at intermediate altitudes is often thoroughly wet, can glide away on very steep slopes.

On Saturday in the Northern Alps, gray skies, heavy cloud cover, many peaks veiled in fog, occasional light snowfall, soon tapering off. In the afternoon, bright, sunny intervals will become more frequent. In the rimline ranges, brilliant sunshine after the fog has dispersed. The NW winds will slacken off but still be brisk in exposed terrain. At 2000 m: -7 degrees at midday, temperatures rising in the evening.

High-pressure front effects on Sunday will create mostly sunny weather, mild temperatures at all altitudes. The snowdrift problem will recede, the wet-snow problem will be at the forefront in regions where fresh snow is ample.