During a night of clear skies, a crust which is capable of bearing loads will form over widespread areas on sunny slopes.
As a consequence of daytime warming and solar radiation this crust then thaws and the snowpack subsequently forfeits its stability.
Wet-snow and gliding avalanches then become possible. In the last few days, only very few wet-snow avalanches have been recorded,
in spite of the mild temperatures and sunny skies.
In the southern Valais as well as in the inneralpine and the southern regions of Grisons more than anywhere else, there are
pronounced weak layers evident which are deeply embedded inside the snowpack. These layers react with particular sensitivity
to moistening. Moist and wet avalanches can sweep away deeper layers of the snowpack there, or even fracture directly in those
layers. They can also be triggered by persons.
The snowpack on south-facing slopes below approximately 2800 m, on east-facing and west-facing slopes below approximately
2400 m, and on north-facing slopes below approximately 1600 m, is thoroughly wet.