1/ Wind and snowpack
During snowfall and in the days that follow,the wind transports the snow. Systematically, it will accumulate on the leeward side (opposite side to the prevailing wind) of mountain passes and high ridges, as well as on slopes where there is rock or ground movement.
Take a good look around you: small indicators help you guess the direction of the prevailing wind. Therefore, you can figure out the slopes where snow will accumulate as snowdrifts and, below these, possible wind slabs.
Sintering of the snow is one of these indicators. Small beads form on the surface of the snow layer. They have a sharp or stepped side. This side is the one in the direction of the wind.
Another indicator: the small trees on the subalpine level. They fight the natural elements to survive. Conifers adapt particularly well and develop a flagbearing appearance by letting their branches die that face the direction of the wind. The side where the tree’s branches will grow horizontally and often at ground level is called the leeward side.
Every ridge or marked relief implies that a snowdrift has formed. It will be more or less higher, more or less overhanging. It's extremely dangerous to go over it. When walking on the ridges, always choose the windy side where there isn't much snow. In any case, keep a few metres back from the edge of the snowdrift. They are nearly always considerably overhanging.