Support the forecast! Support the forecast!

Give to Friends of the Chugach National Forest Avalanche Info Center.

Avalanche: Turnagain

Location: Tincan up to 2,500'

Date:
Observer:
Route & General Observations

Common skin track to the top of the Tincan Trees and up a bit more to 2,500′. It was a storm day on Turnagain Pass.

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 SkierAvalanche Type Soft Slab
Aspect SoutheastElevation 2500ft
Slope AngleunknownCrown Depth 8in
Width 100ftVertical Run 200ft
Avalanche Details

Skier triggered avalanche on the SE facing slope opposite the 'tincan trees'. Triggered from the broad ridge by pushing snow on a steep small rollover. This shallow slab ran 150-200' to the depression/gully below then (we think) sympathetically triggered 3 more pockets on the other side of the gully. These pockets were small - 30' wide and 8-10" deep.

Weak layer was the early December facets.

VERY TOUCHY above treeline !

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

All the signs were present for an unstable snowpack above the trees.

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

Snowing around .5-1" an hour
Winds light in the trees but moderate just above treeline from the North
Temps warm, 30F at at the parking lot and upper-20'sF at 2,500'

Snow surface

3-5" and counting of new snow! This was moist and dense at 1,000' but became lighter and low density at 2,000'. Winds have been moving the snow around above the trees, with such low visibility it was hard to tell how much wind effect was occurring in the Alpine.

Snowpack

Alpine elevations: Unstable. 6-10" slab over weak facets on Tincan. Slab is composed of the new snow + 3-4" of settled snow from Dec 15/16. Facets are from the Dec 1-Dec 14 clear period. This faceted layer is definitely proving to be dangerous. It was exceptionally easy to trigger the above avalanches.

In the Tincan Trees: Loose new snow over loose faceted snow = lots of sluffing and in some areas just enough settlement occurred in the new snow to form shallow 'storm slabs' that propagated 30-50'.

Photos & Video
Please upload photos below. Maximum of 5 megabytes per image. Click here for help on resizing images. If you are having trouble uploading please email images separately to staff.