Support the forecast! Support the forecast!

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

Observation: Turnagain

Location: Tin Can

Date:
Observer:
Route & General Observations

Route
Tin Can parking lot up to skier’s right Hippy Bowl (3,200’)

Weather
Temps in the low 20’s.
Fog bank between 1,200’ and 1,900’. Clear skies and sunshine above 1,900’.
Calm winds
No precipitation

Obvious Signs of instability:
Recent avalanches-Nothing recent in the past 48hrs.
Shooting cracks-NO
Collapsing-NO
Other- Witnessed 2 separate and substantial human-triggered cornice breaks on ridge between Tin Can
common and Hippy bowl (See pics and vid below).

Older wet loose avalanche activity observed on Tin Can and in Todd’s run (likely occurred between 12/7 – 9
during the height of the last storm). 2,300 – 2,700’ appeared to be the common start zone for this older
wet-loose activity.

Glide cracks- We are still mapping glide cracks as best we can. Plenty of these to go around on both Tin
Can and Eddies around the 2,500’ band. Fitz observed a glide crack on the east face of Pyramid yesterday
(12/10) that appears to be widening. Visibility was such that we could not see it today.

Surface Observations
Zero to a trace of snow at road level (1,000’). Very challenging travel between 1,000 – 1,500’ Expert
skiing ability and crampons or studded approach shoes recommended (no joke!)
Thin, supportable rain crust at 1,500’ up to ~2,500’. Fitz said it best; “It’s like skiing on a coral reef.”

2,500’ to 2,800’ the surface very quickly transitions from supportable crust to breakable crust to fist hard
powder in the upper elevations.

Widespread surface hoar (1-6mm) was observed on the surface in open areas between
1,500-3,200’ (extent of our tour). This surface hoar is resting directly on a stout crust at the mid
elevations and fist hard powder above ~2,800’. If buried in tact, (particularly at the mid-elevation band
where SH rests on a firm crust) this could prove a persistent and problematic weak layer with future
storms.

Pit #1 – 3,200’ N Aspect
HS (Height of Snow)= 90cm – 35″
Good strength (ECTN24 @ 40cm down. Fracture but no propagation on a slight hardness change)
Low energy- No propagation potential observed.
Good structure- No persistent weak layers observed

Pit #2 – 3,100’ SW Aspect in wind loaded pocket
Pit results again pointed toward good strength, low energy and good structure with no persistent weak
layers observed.

Other: On the ridge between Tin Can Common and Hippy bowl, my partner and I witnessed 2 separate
parties accidentally trigger significant (School bus sized) cornice falls. One of which took an individual for
about a 15 vertical foot ride onto the slope below. In both instances these cornices broke after several
parties had traversed the ridge. The second cornice impact pulled out only a small slab in steep (~40
degree) terrain. While good news for slope stability, these back-to-back close calls are a good reminder
that cornices deserve a VERY WIDE BERTH if your ski tour takes you along a corniced ridge.

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.