Avalanche

:This article refers to the natural event. For other uses, see Avalanche (disambiguation)

United States Avalanche Danger Scale

In the United States, the following avalanche danger scale is used.

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Probability and trigger

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Degree and distribution of danger

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Recommended action in back country

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Low (green)

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Natural avalanches very unlikely. Human triggered avalanches unlikely. Generally stable snow. Isolated areas of instability.

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Travel is generally safe. Normal caution advised.

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Moderate (yellow)

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Natural avalanches unlikely. Human triggered avalanches possible. Unstable slabs possible on steep terrain.

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Use caution in steeper terrain.

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Considerable (orange)

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Natural avalanches possible. Human triggered avalanches probable. Unstable slabs probable on steep terrain.

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Be increasingly cautious in steeper terrain.

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High (red)

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Natural and human triggered avalanches likely. Unstable slabs likely on a variety of aspects and slope angles.

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Travel in avalanche terrain is not recommended. Safest travel on windward ridges of lower angle slopes without steeper terrain above.

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Extreme (red/black border)

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Widespread natural or human triggered avalanches certain. Extremely unstable slabs certain on most aspects and slope angles. Large destructive avalanches possible.

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Travel in avalanche terrain should be avoided and travel confined to low angle terrain well away from avalanche path run-outs.

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