Pre Alps

Still trigger-sensitive intermediate layers on high-altitude shady slopes

Still trigger-sensitive intermediate layers on high-altitude shady slopes

Main problem: weak layers in upper part of the snowpack. Near ridgelines they can be triggered as a slab avalanche by winter sports enthusiasts on steep shady slopes, but releases tend to remain small. Due to solar radiation and daytime warming, small loose-snow and glide-snow avalanches are possible on sunny slopes.

Temperatures have risen noticeably at high altitude, the proneness to triggering has diminished. In the upper part of the snowpack are expansively metamorphosed (faceted) crystals. These are most triggerable in transition from shallow to deep snow. These zones are not visible to the naked eye. On very steep sunny slopes there is a thin melt-freeze crust on the surface. Elsewhere the snowpack is often powdery. At intermediate altitudes there is surface hoar. Due to solar radiation and daytime warming the snowpack softens on sunny slopes.

Nocturnal hours: cloudless nighttime skies and dry air will bring high outgoing longwave radiation. Monday: sunny weather, mostly cloudless skies. Dry air masses guarantee outstanding visibility. Temperatures will rise. At 2000 m: -1 to +4 degrees. Zero-degree level will rise to nearly 3000 m. Light NE winds.

Tuesday and Wednesday will be sunny, zero-degree level will abide at about 3000 m. Through Wednesday the winds will be light. On Thursday, intensifying W/NW winds. Danger of dry-snow avalanches will diminish. As temperatures rise and solar radiation intensifies, wet-snow and glide-snow avalanche danger will increase during the course of the day.