What Is an Avalanche?
An avalanche is a mass of snow tumbling down a slope. Avalanches are tremendous forces of nature that at their biggest can destroy large sections of mature forest. But even small avalanches can be deadly in certain types of terrain.
Avalanches are directly tied to terrain. A basic requirement is a sufficiently steep slope, although, once in motion, avalanches can run onto flat terrain and even uphill.
Avalanche accidents occur when backcountry travellers are exposed to avalanche terrain during conditions that can produce avalanches.