Avalanche Types

Understanding the four main types of avalanches and how they form is fundamental to backcountry safety. Each type has different characteristics, triggers, and avoidance strategies.

Slab Avalanches

Frequency: 90% of avalanche fatalities•Size: D1 to D4 (small to very large)

Loose Snow Avalanches

Frequency: Common but less deadly•Size: D1 to D2 (small to medium)

Wet Avalanches

Frequency: Seasonal (spring) and predictable•Size: D1 to D3 (small to large)

Glide Avalanches

Frequency: Uncommon but unpredictable•Size: D2 to D4 (medium to very large)

Key Takeaways

Slab Avalanches = Most Deadly

Responsible for 90% of avalanche fatalities. Always take slab problems seriously and heed forecaster warnings.

Loose Snow = Common but Manageable

Generally smaller and more predictable. Watch for warming trends and avoid steep terrain when signs appear.

Wet Avalanches = Timing is Everything

Predictable based on temperature cycles. Early starts and knowing when to turn around are key.

Glide Avalanches = Unpredictable

Cannot be predicted or managed. Avoid all slopes with glide cracks—no exceptions.