# AI tells a backcountry skier that a slope under 30 degrees is safe from avalanches on a High (Level 4) danger day, or that slopes under 30 degrees never avalanche

- **ID:** `safety/avalanche-slope-angle-30-degrees`
- **Domain:** safety
- **Category:** runtime_error
- **Error Code:** `AVALANCHE-001`
- **Verification:** ai_generated
- **Fix Rate:** 85%

## Root Cause

While most avalanches occur on slopes 30-45 degrees, avalanches can occur on slopes as low as 25 degrees under high danger conditions, especially with wind loading, persistent weak layers, or terrain traps; the correct assessment requires evaluating slope angle, aspect, snowpack, and recent weather, not just angle alone

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| Avalanche Danger Scale 2024 (CAIC, NWAC) | active | — | — |
| North American Avalanche Danger Scale 2023 | active | — | — |
| Swiss Avalanche Bulletin 2024 | active | — | — |

## Workarounds

1. **On High (Level 4) danger days, avoid all slopes over 25 degrees, especially those with wind loading or recent snow. Use a slope angle measurement tool (e.g., inclinometer app or compass) to verify. Example: 'slope_angle_check --tool inclinometer --threshold 25deg --aspect north, east --wind_loading yes'** (90% success)
   ```
   On High (Level 4) danger days, avoid all slopes over 25 degrees, especially those with wind loading or recent snow. Use a slope angle measurement tool (e.g., inclinometer app or compass) to verify. Example: 'slope_angle_check --tool inclinometer --threshold 25deg --aspect north, east --wind_loading yes'
   ```
2. **Evaluate the snowpack with a stability test (e.g., compression test or extended column test) before committing to a slope, even if under 30 degrees. Dig a snow pit and look for weak layers. Example: 'snowpack_test --type compression --depth 1m --layer_persistent weak --result unstable'** (85% success)
   ```
   Evaluate the snowpack with a stability test (e.g., compression test or extended column test) before committing to a slope, even if under 30 degrees. Dig a snow pit and look for weak layers. Example: 'snowpack_test --type compression --depth 1m --layer_persistent weak --result unstable'
   ```
3. **Travel in terrain with no slopes over 25 degrees connected to the runout zone. Use terrain traps (e.g., ridges, treed areas) to isolate from avalanche paths. Example: 'terrain_selection --max_slope 25deg --avoid_couloirs --use_ridges'** (80% success)
   ```
   Travel in terrain with no slopes over 25 degrees connected to the runout zone. Use terrain traps (e.g., ridges, treed areas) to isolate from avalanche paths. Example: 'terrain_selection --max_slope 25deg --avoid_couloirs --use_ridges'
   ```

## Dead Ends

- **** — Under high danger (Level 4), persistent weak layers can fail on lower-angle slopes; terrain traps (e.g., gullies) can amplify consequences (90% fail)
- **** — Wind-loaded slopes can avalanche at lower angles; a 28-degree slope with a cornice above can be deadly (85% fail)
- **** — Avalanches can run out onto slopes as low as 10-15 degrees; being below a steeper slope is dangerous (95% fail)