Hochschwab Mountains

Considerable avalanche danger - caution urged towards snowdrift-problem and wet-snow problem

Considerable avalanche danger - caution urged towards snowdrift-problem and wet-snow problem

Due to intensifying SW winds, fresh snow from Tuesday was transported to shady leeward slopes and is now prone to triggering. Due to stormy NW winds, fresh snowdrift accumulations are now being generated near to and distant from ridglines in all aspects. Particularly on W/N/E facing slopes and in gullies and bowls, even minimum additional loading can trigger a slab avalanche. On steep shady slopes avalanches can fracture down to deeper layers and grow to large size. Due to higher temperatures and solar radiation, fresh layers on steep slopes can naturally trigger as a wet-snow avalanche. On steep slopes with smooth ground, glide-snow avalanches can release. On exposed slopes it is hard and icy, danger of being forced to take a fall.

Wherever there was little wind impact on Sunday when the snow fell, but which was then transported by brisk SW winds to shady slopes, the bonding to the often loose, soft snowpack is insufficient. Also, due to stormy NW winds, fresh snowdrift accumulations are being generated, deposited atop still loose old snow and thus, prone to triggering. In addition, there are still weak layers inside the old snow (faceted crystals near crusts) which can be triggered, particularly in very steep terrain. On sunny slopes and at lower altitudes the fresh snow has often bonded well with the old snowpack. Warmth, solar radiation and rainfall will further moisten the snowpack and destabilize it. This could lead to wet-snow - and, in the case of it becoming thoroughly wet - to glide-snow avalanches. Exposed terrain are often hardened, due to weather, in places they are icy.

Wedged between a high over the Iberian peninsula and a low over northern Europe, a stormy NW air current is building up in the Eastern Alps. In the barrier cloud regions of the Northern Alps the mountains will disappear into fog and clouds. A cold front in the afternoon can bring repeated bouts of rain, snow, graupel. In between there will be sunny phases. The southern flank of the Alps will have better weather conditions, mostly sunny and only brief showers. The NW to W wind will reach storm strength, even gale-strength in exposed terrain. Temperature at middday still high. At 2000 m: 0 to +4 degrees, then dropping by evening. At 1500 m from +2 to +7 degrees before the drop.

On Friday the stormy winds will slacken off, as of midday the air current will shift to southwesterly, though winds in the rimline massifs will intensify somewhat. As a result of the next warm front it will become extremely mild up to high altitudes by evening. Variably cloudy, but mostly dry. Avalanche danger could relax somewhat due to the warmth, but in the afternoon the danger levels of moist-snow avalanches will rise again in steep terrain.