Weisseck, Muhr Valley

Trigger-sensitive snowdrifts in high alpine regions, daytime cycle of wet-snow problem

Trigger-sensitive snowdrifts in high alpine regions, daytime cycle of wet-snow problem

Avalanche danger above 2600m is CONSIDERABLE, down to 2000 m MODERATE, below that altitude LOW but rises to Danger Level 2 as of midday. The fresh snowdrifts formed by fresh snow and strong northerly winds are triggerable particularly by large additional loading. Frequency of danger zones and depth of the drifts increase with ascending altitude. Most danger zones are in E/S aspects in ridgeline terrain and in wind-loaded gullies and bowls. Naturally triggered glide-snow avalanches on extremely steep grassy slopes; and in sunny phases: loose-snow avalanches in rocky steep terrain.

Fresh snow + snowdrifts (for 3 days: 50-80 cm in high alpine regions, up to 100 cm from place to place) are bonding well between 2100 and 2400m with the moist snowbase. Above that altitude, bonding deteriorates, as artificial triggerings have demonstrated in E/S aspects. Due to warmth and solar radiation, fresh snow will forfeit its firmness, superficial melt-freeze crusts rapidly lose their firmness.

On Monday, mostly sunshine, although hampered by clouds passing through. Little wind. Noticeable warming. At 2000 m: from -5 to +2 degrees. On Monday night, only thin cloud and adequate outgoing longwave radiation. Tuesday will be sunny, only thin cirrus clouds. Southerly foehn wind in the Tauern region, 30-50 km/hr, elsewhere the winds will not be a disturbance. It will be a notch warmer. At 2000 m: 5-8 degrees, at 3000 m: +1 degree.

In high alpine regions, moderate snowdrift problem persists, although the proneness to triggering is diminishing. Pronounced daytime cycle of wet-snow avalanche danger up to high altitude.