Avalanche Danger Scale Definitions Review

[Hacksaw]

With all the avalanche action happening here in Colorado the news media (TV, radio and print) have been talking about the avalanche danger. But, when they start talking about the avalanche danger, they consistly screw-up on the definition of each danger level.

So, let's have a little review here. I know that I cover this in my courses a lot.

People seem to have a real problem understanding the difference between the Moderate and Considerable dangers levels. As it turns out more folks are killed during Considerable danger then during High. I think that a lot of this is because people don't understand the "Considerable" danger level.

Avalanche forcasters decided on what danger level to post, based on if natural avalanches are happening or the likelyhood of human triggered avalanches happening. So, keep that in mind.

Avalanche Danger -- Natural triggered -- Human triggered


LOW --- Unlikely --- Unlikely

Moderate --- Possible --- Possible

Considerable --- Possible --- Probable

High --- Likely --- Likely

Extreme --- Certain --- Certain

To me, the word "Probable," means that there is a VERY good chance of something happening. The dictionary defines Probable as "likely to be or become true or real."

I hope this helps folks. Reading the daily avalanche center forecast is the best way to keep up on the weather and snowpack trends. By becoming a "Friend," of your local avalanche center you can have the daily forecasts emailled to you. And it will give you a nice warm fuzzy feeling, that you are supporting you're tipically underfunded avalanche center.

For the Colorado Avalanche Information Center

http://avalanche.state.co.us/

Cheers,
Halsted Morris

[pechelman]

bump for this thread to also include the other one which has received a lot of discussion

http://www.tetongravity.com/forums/s....php?p=1633619

[sarge1957]

For a more detailed overview on hazaed ratings, see the Avalanche Safety section on the "Lost and Found" DVD. We review hazard ratings and cornice cutting in this years lesson.

Sarge

[nomensteven]

The CAA's definitions are as follows:
LOW: Natural avalanches very unlikely. Human triggered avalanches unlikely. Travel is generally Safe. Normal caution advised.

Moderate: Natural avalanches possible. Human triggered avalanches possible. Use caution in steeper terrain on certain aspects.

Considerable: Natural avalanches possible. Human triggered avalanches probable. Be increasingly cautious in steeper terrain.

High: Natural and human triggered avalanches likely. Travel in avalanche terrain is not recommended.

Extreme: Widespread natural and human triggered avalanches certain. Travel in avalanche terrain should be avoided and travel confined to low angle terrain well away from avalanche path run-outs.