Goldberg Group Central

Rapid daytime increase in avalanche danger

Rapid daytime increase in avalanche danger

Avalanche danger below 2600m is MODERATE in general, above that altitude danger is LOW. Danger of wet-snow and glide-snow avalanches rises during the morning significantly, reaching CONSIDERABLE danger elow 2600m during the course of the day. Backcountry tours and ascents to huts should be terminated early in the day. Morning: Following a night of mostly clear skies, good touring conditions prevail in the morning hours. Below 2600m there is moderate danger of naturally triggered glide-snow avalanches on steep (>30°) slopes. Runout zones and areas below glide cracks should be circumvented. In addition, isolated danger zones for dry-snow slab avlanches exist on very steep (>35°) shady slopes at high altitude, where avalanches can trigger in the weak snow and reach medium size. Danger zones are not visible to the naked eye. During the course of the day: Due to solar radiation and daytime rise in temperatures, danger of wet-snow avalanches rapidly increases. A soft and increasingly weak snowpack is an indicator of rising danger. Particularly on E/S/W facing slopes below 2600m, but also on shady slopes below 2200m, avalanches in the plummet paths can sweep along the wet snowpack and reach medium size, in isolated cases even large size if there is sufficient snow. Caution urged where such risks prevail.

The snowpack on E/S/W facing slopes is thoroughly wet and, depending on aspect, even wet down to the ground and zero-degree isotherm. Also on shady slopes the snowpack was moistened up to high altitudes on Monday due to warmth and diffuse radiation. In the mostly cloudy nigt the snowpack cannot radiate its warmth outwards. During the dayime it softens further and forfeits its firmness. Free water on grassy slope ground enhances the gliding of the snowpack. On shady slopes at high altitudes the upper part has isolated weak and trigger-sensitive layers; layers more deeply embedded inside the snowpack are currently unlikely to trigger. Below the treeline there is little snow on the ground, above the treeline the snow depths are below average.

On Thursday, reduced visibility due to clouds, only scattered in Tauern and Nockberge. As of midday, visibility will improve. Winds will be light from the west, southerly winds in the Tauern. At 2000m: 3-6 degrees; at 3000 m: -2 degrees.

Rainwater on Friday will further weaken the snowpack. Particularly on shady slopes, increasingly frequent wet-snow avalanches are expected.