Ski Guides: Avalanches

An avalanche occurs when a mass of snow, ice, and debris suddenly breaks loose and moves rapidly downhill. Avalanches vary in size and type, but they can be extremely dangerous, especially in steep, snow-covered terrain.

Avalanche Danger Levels & What They Mean

Avalanche risk is categorized into five levels, typically issued in avalanche forecasts:

1. Low Risk (Green - Level 1)

✔️ Snow is generally stable
✔️ Avalanches are unlikely, except in very steep terrain
✔️ Safe for off-piste skiing and snowboarding, but always stay cautious

2. Moderate Risk (Yellow - Level 2)

✔️ Some unstable areas, mainly on steep slopes
✔️ Avalanches are possible with a significant trigger (e.g., skiers, snowboarders)
✔️ Off-piste skiing is still possible, but awareness is needed

3. Considerable Risk (Orange - Level 3) (Most Avalanche Fatalities Occur at This Level)

✔️ Snowpack is moderately to poorly stable
✔️ Avalanches are likely on steep slopes
✔️ Off-piste skiing is dangerous without proper avalanche safety gear and knowledge

4. High Risk (Red - Level 4)

✔️ Unstable snowpack with widespread avalanche activity
✔️ Avalanches are likely, even on moderate slopes
✔️ Off-piste skiing is not recommended—danger levels are critical

5. Extreme Risk (Black - Level 5)

✔️ Avalanche activity is widespread and highly destructive
✔️ Spontaneous avalanches occur, even on gentle slopes
✔️ All off-piste areas and backcountry travel should be avoided

Types of Avalanches

There are several types of avalanches, each with different causes and behaviors:

1. Slab Avalanche (Most Dangerous Type)

• A thick slab of snow breaks off and slides down as a unit
• Can be triggered by skiers or snowboarders
• Often occurs after fresh snowfall or wind-packed snow

2. Loose Snow Avalanche ("Sluff" Avalanches)

• Begins at a single point and fans out as it moves downhill
• Common in fresh, unconsolidated snow
• Usually small but can still pose a risk in steep terrain

3. Wet Snow Avalanche

• Occurs when rising temperatures cause snow to become heavy and unstable
• Can be slow-moving but powerful and destructive

4. Glide Avalanche

• Snowpack slides slowly over time due to a weak layer underneath
• Difficult to predict but can release suddenly

Avalanche Safety & Prevention Tips

✔️ Check Avalanche Reports Daily – Always review local avalanche forecasts before heading into the mountains
✔️ Carry Essential Avalanche Gear – A transceiver, probe, and shovel are must-haves for off-piste skiing
✔️ Ski in Groups – Never ski alone in avalanche-prone areas
✔️ Stick to Safe Terrain – Avoid steep, convex slopes and known avalanche zones
✔️ Learn Avalanche Safety Skills – Take an avalanche awareness course to understand risks and rescue techniques