Avalanche: Summit

Location: Summit Area

Route & General Observations

Colorado to 2300′ on a generally SE aspect

Avalanche Details
If this is an avalanche observation, click yes below and fill in the form as best as you can. If people were involved, please provide details.
Trigger NaturalRemote Trigger Unknown
Avalanche Type UnknownAspect South
Elevation 3500ftSlope Angleunknown
Crown DepthunknownWidth 500ft
Vertical Run 1000ft  
Avalanche Details

See photos below for examples and the largest slides, including:
Moose: Numerous D2-3 on south to west aspects.
Lodestar: D3 on west aspect from ridgeline, with a deep crown
Areawide: D1.5 - D2 slabs generally well below ridgeline or at treeline - small debris piles evident up valleys to the west of Colorado under slopes where we couldn't see the start zones. Examples from Spirit Walker and Wilson South below.

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?No
Collapsing (Whumphing)?Yes
Cracking (Shooting cracks)?No
Observer Comments

Some world class, deep sounding whumphs at 2300' as we approached trees at the top of our route. For one where I was standing still - triggered as my partner was at a shallow spot near trees - I felt the snowpack drop a solid inch under foot! Willows would move 100+ yards away... these ones went a long distance. No formal stability tests, but a quick dig revealed large facets/depth hoar at the bottom of the snowpack, under about 100-120cm of snow at this elevation, along with some fairly subtle density changes above that... so I'm guessing we found thinner spots that reached the facets at the ground for these whumphs.

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

Clear, temps in the teens, light occasional winds from the north

Snow surface

4-6" of ski penetration along the entire route, with 3-6mm surface hoar in areas not sheltered by trees. Boot penetration of your waist at transition points at 2300' and 1800'. A thin crust from the New Years storm was ~3" below the surface up to 1500' but dissipated after that!


No formal stability tests.

Photos & Video
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