AVALANCHE-SAFE-ERR-004 safety system_error ai_generated partial

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 to reduce risk

ID: safety/avalanche-slope-angle

Also available as: JSON · Markdown · 中文
80%Fix Rate
87%Confidence
1Evidence
2024-02-05First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
North American Avalanche Danger Scale (CAIC/NWAC) active — — —
Avalanche Canada Forecast v2.1 active — — —
European Avalanche Danger Scale (EAWS) 2023 active — — —

Root Cause

Avalanches can occur on slopes as low as 25 degrees, especially on High (Level 4) days where persistent weak layers exist; skiing one at a time reduces but does not eliminate risk, as avalanches can be triggered from above or below; terrain traps (e.g., gullies, cliffs) amplify consequences even on moderate slopes.

generic

中文

雪崩可能发生在低至25度的斜坡上，特别是在高度（4级）危险日存在持续薄弱层时；一次滑一个可降低但无法消除风险，因为雪崩可能从上方或下方触发；地形陷阱（如沟壑、悬崖）即使在中度斜坡上也会放大后果。

Official Documentation

https://avalanche.org/avalanche-education/

Workarounds

  1. 85% success On High (Level 4) days, travel only on slopes under 25 degrees with no terrain traps above (e.g., avoid gullies, cliffs). Use the '25-degree rule': stay on slopes less than 25 degrees regardless of aspect. 
    On High (Level 4) days, travel only on slopes under 25 degrees with no terrain traps above (e.g., avoid gullies, cliffs). Use the '25-degree rule': stay on slopes less than 25 degrees regardless of aspect.
  2. 78% success Perform a compression test (CT) and extended column test (ECT) on a representative slope before committing. If ECT fails (propagation), avoid the slope entirely. 
    Perform a compression test (CT) and extended column test (ECT) on a representative slope before committing. If ECT fails (propagation), avoid the slope entirely.
  3. 82% success Use terrain management: ski on ridges or wind-scoured slopes, avoid leeward slopes with wind loading. Check avalanche forecast for specific elevation bands and aspects. 
    Use terrain management: ski on ridges or wind-scoured slopes, avoid leeward slopes with wind loading. Check avalanche forecast for specific elevation bands and aspects.

中文步骤

  1. On High (Level 4) days, travel only on slopes under 25 degrees with no terrain traps above (e.g., avoid gullies, cliffs). Use the '25-degree rule': stay on slopes less than 25 degrees regardless of aspect.
  2. Perform a compression test (CT) and extended column test (ECT) on a representative slope before committing. If ECT fails (propagation), avoid the slope entirely.
  3. Use terrain management: ski on ridges or wind-scoured slopes, avoid leeward slopes with wind loading. Check avalanche forecast for specific elevation bands and aspects.

Dead Ends

Common approaches that don't work:

  1. Check local avalanche forecast (e.g., CAIC, NWAC) and perform stability tests (ECT, CT) 70% fail

    Assuming slope angle alone determines safety ignores snowpack structure, weather history, and terrain traps; 25-30 degree slopes are common avalanche paths.

  2. Use proper group management: travel one at a time but with safe zones and communication 60% fail

    Skiing one at a time does not prevent avalanches triggered by the skier above; cornice falls or remote triggers still pose risk.

  3. Avoid slopes >25 degrees on north aspects; choose low-angle terrain (<25°) on south aspects 65% fail

    Ignoring aspect and elevation; on High danger, north-facing slopes above treeline are most hazardous.