What do resorts do?
Resorts in Europe and the U.S ensure that by the time their ski lifts open in the morning the entire mountain has been examined by ski patrol and the avalanche risk for that day has been thoroughly assessed. Once this assessment has been made the mountain notify the public of the level of danger using these scales:
| Grade of risk: | 1. Low | |
| Stability of snow pack: | The Snowpack is generally well stabilised. |  |
| Probability of release: | Release of avalanches is only possible on very few and very steep slopes. Only small spontaneous avalanches are to be expected. | |
| Sign: | Yellow |
| Grade of risk: | 2. Moderate | |
| Stability of snow pack: | The snowpack is only moderately stabilised on some steep slopes* but otherwise generally well stabilised. | |
| Probability of release: | Large additional loads** may release avalanches, especially on steep slopes of the stated altitude and orientation. Larger spontaneous avalanches are not to be expected. | |
| Sign: | Yellow |
| Grade of risk: | 3. Considerable | |
| Stability of snow pack: | The snowpack is only weakly to moderately stabilised on many steep slopes*. |  |
| Probability of release: | Release of avalanches are likely by moderate additional load** on the most steep slopes. Occasional spontaneous avalanches are possible. | |
| Sign: | Checked Black and Yellow |
| Grade of risk: | 4. High | |
| Stability of snow pack: | The snowpack is weakly stabilised on the most steep slopes*. | |
| Probability of release: | Release of avalanches are likely from low additional load** on steep slopes. Occasional medium sized, sometimes also large spontaneous avalanches have to be expected. | |
| Sign: | Checked Black and Yellow |
| Grade of risk: | 5. Very High | |
| Stability of snow pack: | The Snowpack is generally weakly stabilised and mostly unstable. |  |
| Probability of release: | Numerous large spontaneous avalanches have to be expected. | |
| Sign: | Black |
| Grade of risk: | 1. Low | |
| Stability of snow pack: | Generally stable snow. Isolated areas of instability. |  |
| Probability of release: | Natural avalanches very unlikely. Human triggered avalanches unlikely | |
| Sign: | Green |
| Grade of risk: | 2. Moderate | |
| Stability of snow pack: | Unstable slabs possible on steep terrain. | |
| Probability of release: | Natural avalanches unlikely. Human triggered avalanches possible. | |
| Sign: | Yellow |
| Grade of risk: | 3. Considerable | |
| Stability of snow pack: | Unstable slabs probable on steep terrain. |  |
| Probability of release: | Natural avalanches possible. Human triggered avalanches probable. | |
| Sign: | Orange |
| Grade of risk: | 4. High | |
| Stability of snow pack: | Unstable slabs likely on a variety of aspects and slope angles. |  |
| Probability of release: | Natural and human triggered avalanches likely. | |
| Sign: | Red |
| Grade of risk: | 4. Extreme | |
| Stability of snow pack: | Extremely unstable slabs certain on most aspects and slope angles. Large, destructive avalanches possible. |  |
| Probability of release: | Widespread natural and human triggered avalanches certain. | |
| Sign: | Red with black border |
