Data
Class
Information
Category
Observations
Made
Red Flag
Values
Your
Observations
Weather Precipitation Type Rain/heavy wet snow


Intensity >3 cm / hr


Accumulation >30 cm/ 12 hr

Wind Speed Strong enough to move snow


Direction Moving snow onto/across route


Duration Long

Temperature Current ≥ 0◦c


Maximum ≥ 0◦c


Minimum ≥ 0◦c


Trends Rapid change

Solar radiation Cloud cover Allowing a lot/ intensifying


Intensity Strong


Duration Long
Snowpack Snow Cover Height < 1.5m


Strength Weak


Variability High

Layers Strength Strong over Weak


Temperature Near/= 0◦c


Grain Characteristics Large, loosely packed, angular grains

Bonding Strength Compression test ≤20 Rutschblock ≤4


Plane Characteristics Smooth, Clean


Failure Layer Large, loosely packed, angular grains

Whumping Initiation Natural/Human Trigger


Propagation Far (>3m)


Extent Widespread
Avalanche
Activity
When Current Observed


Recent <24 hr (Maritime climate)
<48 hr (Continental)



Past If condition still exists

Where Area Widespread


Terrain Type Similar to route


Terrain Traps Angle/Aspect Traps exist where avalanches are running

What Natural Triggers All Natural Triggers


Human Triggers All Human Triggers

How Destructive Potential ≥ Class 2


Propagation Wide fracture lines running far


Failure Layer Large, loosely packed, angular grains