the U.S. and Canada, a five-category estimation of the avalanche danger:
Low, Moderate, Considerable, High and Extreme.
Avalanche forecasters use the Danger Scale to communicate
travel advice, the likelihood of avalanches, and the size and distribution of avalanches.
The ratings are used in backcountry avalanche bulletins accessed via
the web, email, or a voice recording, and are usually accompanied
by a more detailed discussion of the avalanche danger.