Observation: Hatcher Pass

Location: Marmot Test Slopes

Route & General Observations

Short tour to Marmot Test Slopes for Instability Testing.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?Yes
Collapsing (Whumphing)?Yes
Cracking (Shooting cracks)?Yes
Observer Comments

Numerous recent, large, natural avalanches on all aspects at mid to upper elevations which failed during or just after the storm. A few crowns observed were approximately 800-1000┬┤wide, measured on google earth. Most were 100-300 feet wide.
Avalanches ranged from D2-3 with the majority in the D2 range, crowns appeared to be 2-3 feet deep. Avalanches wrapped around terrain features. Most failed at the ground.
Numerous large whumphs and shooting cracks up to 50 feet long throughout my tour.

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

Clear skies for most of the day, increasing clouds in afternoon.
1pm: calm to light breeze, WNW, 22F

Snow surface

Low density, new snow
HST 61cm


HS 75cm
Poor Structure
Moderate Strength
High Propagation Propensity

Photos & Video
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