Noun. The
snow that is set into movement when snowboarding or
skiing in steep terrain (above 40 degrees). Due to the often
loose cohesion of the powders top layer, more
snow can be accumulated by the already moving
snow. If the slope is sufficiently steep for a a couple hundred meters, the sluff can get very fast. One turn on top of a steep face can cause a sluff that reaches avalanche-like proportions.
A relatively small sluff can knock a snowboarder/skier off his
feet and take him for a fast and dangerous ride down to the end of the slope or over a cliff.
Sluff is one of the mayor difficulties in big mountain snowboarding/skiing, yet it also presents an interesting challenge and is very spectacular to watch. The techniques to deal with sluff while riding are called sluff management.