Avalanche: Turnagain

Location: Eddies

Date:
Observer:
Route & General Observations

Eddies to 2200′

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 UnknownRemote Trigger Unknown
Avalanche Type UnknownAspect Unknown
ElevationunknownSlope Angleunknown
Crown DepthunknownWidthunknown
Vertical Rununknown  
Avalanche Details

Slab avalanche on sunnyside as reported 11/26 observed up valley; in addition, several similar slides - pictured below - were likely from yesterday or today as well.

Some older, deep crowns were visible as well on sunnyside and blueberry hill - hard to put a date on them from so far away - but they are at least a few days old (partly filled in by recent storm). These were more obvious to the naked eye then the slides from the last two days.

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)?No
Cracking (Shooting cracks)?No
Observer Comments

Only red flags were avalanches discussed above, but we stayed low.

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

Valley fog obscured skies in the AM, changing to broken -> few clouds by afternoon.
IT FELT REALLY COLD BY AFTERNOON - single digits in AM and dropping throughout the day
Calm winds.

Snow surface

1-2" of new snow fell overnight. While this new snow was noticeably denser than the snow below it and could be carefully picked up in small blocks, it was still fist hard and quite soft. Ski penetration today of 30-40cm, slightly less than midweek.

Snowpack

At 2100' new snow since 11/22 has consolidated to 50cm. Within the storm snow, a layer of buried stellars - guessing they were covered on 11/24 - is visible in pit wall. Above this layer is 20cm of fist hard snow that is barely cohesive enough to act as a slab in hand pits and shovel tilt tests (see results and structure below). Below the buried stellars, snow that fell on 11/22 and 11/23 is gaining strength, and today was 4 fingers hard at the new/old interface. This interface has large (5mm+) buried surface hoar over facets.

Full structure and stability tests from today are below, but we also dug nearby on 11/25:
On 11/25: CT 3, 9 RP and ECTP 3 down 55cm on the 11/22 buried surface hoar.
On 11/27: CT 14, 17 RP and ECTN 14 down 50cm on the 11/22 buried surface hoar.
While our ECT on 11/27 didn't propagate across the entire column, it was close... propagating across 80% of the block.
Subjectively, the CTs and ECT 'popped' more today than 11/25, albeit with more taps before a result was produced.

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.