The main parameter in Avalanche Size classification is the Destructive Potential. When the Destructive Potential is not obvious or is difficult to estimate, we apply the Runout Classification.
The Destructive Potential of an avalanche is estimated according to the amount of snow in the debris, and a size is assigned. The objects on the following list (people, vehicles, trees) must be pictured on the avalanche path or at the beginning of the runout zone, in order to estimate the damages an avalanche would cause them.
Note: The destructive potential of an avalanche is a function of its mass, speed and density, as well as of the length and section of the avalanche zone.
Avalanche size scale updated with the changes introduced by the EAWS from the winter season 2018-19.
Relatively harmless to people with minimal danger of burying (danger of falling).
Snow relocation typically stops before the end of a slope.
Could bury, injure or kill a person.
Typically stops at the end of a slope.
Could bury and destroy a car, damage a truck, destroy small buildings or break a few trees.
Could traverse flat areas (considerably below 30º) over distances of less than 50 m.
Could destroy a railway car, large truck, several buildings or a piece of forest.
Traverses flat parts (considerably below 30º) over distances >50 m and can reach valley ground.
Could gouge the landscape. Disastrous damage potential.
Reaches valley ground. Largest snow avalanche known.