The entire snowpack is gliding on the ground, typically on smooth ground such as grassy slopes or smooth rock zones. High activity of glide-snow avalanches is typically related to a thick snowpack with no or only few weak layers. Glide-snow avalanches can occur both with a cold dry snowpack and with a warm moist or wet snowpack. The release of a glide-snow avalanche is difficult to predict, although in many cases glide cracks open prior to release.
Avalanche types and trigger
- Glide-snow avalanches; cold dry or 0 °C-isothermal wet snowpack
- Almost exclusively natural avalanches. Human and artificial triggering is very unlikely.
Primarily on smooth ground and on slopes of any aspect, but more often on sun-exposed slopes.
Position of the weak layer in the snowpack
Interface between the ground and overlaying snowpack.
Glide-snow avalanches are caused by a loss of friction at the snow-ground interface due to the presence of liquid water.
Days to months; occasionally during entire winter-season. The release can occur at any time during the day. In spring, glide-snow avalanches occur often during the second part of the day.
How to manage?
Identification of the problem in the field
The glide snow problem can often be recognized by the presence of glide cracks, which are often pre-cursors of glide snow avalanche release. However, the presence of glide cracks does not indicate imminent avalanche release, which is nearly impossible to predict. Avalanche release without pre-existing glide cracks is also common.
Avoid areas close to glide cracks.