Weisseck, Muhr Valley

Fresh snowdrift accumulations at high altitudes

Fresh snowdrift accumulations at high altitudes

Avalanche danger is LOW. Weak layers in the old snow (above about 2500m) can be triggered in isolated cases, i.e. superficially release a freshly formed slab which then fractures down to a more deeply embedded layer. This applies particularly to wind-protected zones, areas at the foot of rock walls, and wind-protected bowls. Danger zones are small and difficult to recognize in places. Avalanches which release grow rarely to medium size. From zones which have not yet discharged, smooth grassy slopes, rock plates, isolated small glide-snow avalanches can release.

An analysis of the snowpack stability in the western Hohe Tauern (see also our blog) on Wednesday showed that our estimates were correct: the snowpack at high altitudes shows immense impact from strong winds, wind crusts and loose snow alternate over small areas. Between the predominantly shallow snowpack masses there are soft layers embedded which can fracture, but in most cases there is no “slab” on top of them. A cohesive snowpack is limited to leeward bowls. Strong wind impact and some fresh snow on Thursday will not change that situation. On sunny slopes there are shallow superficial melt-freeze crusts evident. Above 2500 m the snowpack layering is often unfavourable due to a weak fundament and soft, faceted crystal layers, plus depth hoar. This applies particularly to wind-protected slopes. Snow depths are highly varied. Below 1800 m there is hardly any snow on the ground.

Storm-strength westerly winds will be blowing from the start, intensifying during the daytime hours, reaching 90 km/hr. Heavy cloud cover will predominate, rainfall or snowfall will be minor, at high altitudes about 5 cm of snow is expected. Snowfall level at 1600 m, but rain will fall in part up to 2000 m. At 2000 m: 0 degrees, at 3000 m: -6 degrees.On Friday residual clouds will soon disperse, then sunshine and good visibility. Some light foehn winds from the south (30-40 km/hr). At 2000 m: +1 degree; at 3000 m: -3 degrees.

At high altitudes, small loose snow slides from the fresh fallen snow are possible on steep sunny slopes. Otherwise, no significant change is anticipated.