# AI tells a backcountry skier that a slope under 30 degrees is safe from avalanches on a High (Level 4) danger day, or that they can ski one at a time without risk

- **ID:** `safety/avalanche-slope-degree`
- **Domain:** safety
- **Category:** physical_safety
- **Error Code:** `AVALANCHE-ANGLE-ERR`
- **Verification:** ai_generated
- **Fix Rate:** 77%

## Root Cause

Avalanche danger ratings are not solely slope-angle dependent; factors include snowpack instability, wind loading, terrain traps, and trigger points. Even slopes under 30 degrees can avalanche if wind-loaded or if the snowpack is weak; skiing one at a time does not eliminate risk if the slope is connected to a trigger zone above.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| danger_scale | active | — | — |
| terrain_classification | active | — | — |

## Workarounds

1. **Use the Avalanche Terrain Exposure Scale (ATES) to classify terrain, and check the local avalanche forecast (e.g., https://avalanche.org). On High danger days, avoid all avalanche terrain (slopes >25 degrees with wind loading or weak snowpack).** (85% success)
   ```
   Use the Avalanche Terrain Exposure Scale (ATES) to classify terrain, and check the local avalanche forecast (e.g., https://avalanche.org). On High danger days, avoid all avalanche terrain (slopes >25 degrees with wind loading or weak snowpack).
   ```
2. **Perform a full snowpack test (e.g., compression test, extended column test) to assess stability before skiing any slope. Carry avalanche safety gear (transceiver, probe, shovel) and travel one at a time through safe zones only.** (75% success)
   ```
   Perform a full snowpack test (e.g., compression test, extended column test) to assess stability before skiing any slope. Carry avalanche safety gear (transceiver, probe, shovel) and travel one at a time through safe zones only.
   ```

## Dead Ends

- **Check only slope angle with an inclinometer app** — Angle alone is insufficient; must also assess snowpack, weather, and recent avalanche activity. Many avalanches occur on 30-35 degree slopes. (75% fail)
- **Ski one at a time and have everyone else watch from the bottom** — Watching from the bottom is dangerous; if an avalanche occurs, the observer may be caught. Safe zones are on ridges or above the start zone. (80% fail)
- **Stay on slopes under 25 degrees to be completely safe** — Even low-angle slopes can avalanche if wind-loaded or if the slope is connected to a steeper trigger zone above. Terrain traps (e.g., gullies) increase risk. (65% fail)