North American Avalanche Danger Scale

LOW DANGER
...snow is generally stable with only isolated pockets of instability. Natural avalanches are very unlikely, while human triggered avalanches are unlikely. Backcountry travel is generally safe. Normal caution is advised.

MODERATE DANGER
...unstable slab layers are possible on steep terrain. Natural avalanches are unlikely, while human triggered avalanches are possible. Backcountry travelers should use caution in steeper terrain or certain aspects.

CONSIDERABLE DANGER
...unstable slab layers are probable on steep terrain. Natural avalanches are possible, while human triggered avalanches are probable. Backcountry travelers should be very cautious in steeper terrain. Be aware of potentially dangerous areas of unstable snow.

HIGH DANGER
...unstable slab layers are likely on a variety of aspects and slope angles. Both natural and human triggered avalanches are likely. Travel in avalanche terrain is not recommended. Safest travel is on windward ridges or on lower angle slopes without steeper terrain above.

EXTREME DANGER
...extremely unstable slab layers exist on most aspects and slope angles. Widespread natural and human triggered avalanches are certain . Large destructive avalanches are possible. Travel in avalanche terrain should be avoided and travel confined to low angle terrain well away from avalanche path runouts.