Avalanche Danger Scale

Web Author: Dale Atkins

©1998 Colorado Avalanche Information Center

The following Danger Scale is used by avalanche centers in the United States. Except for minor changes in terminalology it is also used in Canada and Europe.

LOW (green) Natural avalanches very unlikely. Human triggered avalanches unlikely. Generally stable snow; isolated areas of instability. Travel is generally safe. Normal caution advised.

MODERATE (yellow) Natural avalanches unlikely. Human triggered avalanches possible. Unstable slabs possible on steep terrain. Use caution in steeper terrain on certain aspects.

CONSIDERABLE (formerly known as MODERATE TO HIGH) (orange) Natural avalanches possible. Human triggered avalanches probable. Unstable slabs probable on steep terrain. Be more cautious in steeper terrain. Be aware of potentially dangerous areas of unstable snow. (Changed to "considerable" to follow the international standard)

HIGH (red) Natural and human triggered avalanches likely. Unstable slabs likely on a variety of aspects and slope angles. Travel in avalanche terrain not recommended. Safest travel on windward ridges or lower angle slopes without steeper terrain above.

EXTREME (black) Widespread natural or human triggered avalanches certain. Extremely unstable slabs on most aspects and slope angles. Large destructive avalanches possible. Travel in avalanche terrain should be avoided and travel confined to low angle terrain well away from avalanche path runouts.

 

Web Author: Dale Atkins

©1998 Colorado Avalanche Information Center