Observation: Turnagain

Location: Center Ridge Meadows

Date:
Observer:
Route & General Observations

10:00-16:00
All three groups toured within center ridge meadows with a focus on teaching and conducting instability tests. Beautiful day overall as skies opened up and allowed us to see recent storm effect and releases at higher elevations.

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

Recent point release avalanches up to D1 observed at all elevations of Seattle Ridge, with previous below treeline D1-D2 crown still visible from 1/12 observation.
No cracking or collapsing
No alarming results with test slopes.

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

Obscured trending to Broken by noon.
Light trending to calm NE winds with no observed gusts/plumes.
29°F at 1,200' (11:30)
S-1 to S1 at 09:45-11:00 at 1,000’
No riming observed

Snow surface

900’ to 1,000’: 1” to 2” of smooth, moist, medium density surface snow over low density, stellar-dendrites.
1,000’ to 1,200’: 2” Low density, right side up structure.
Ski/Boot Penetration: 40 cm / 80 cm

Snowpack

Our focus was to teach and assess recent storm accumulation and reactivity within the upper snowpack.
Instability tests at 1,200’ showed good structure, moderate strength and low propagation potential.
Compression tests showed broken and resistant fractures and moderate results within the low density storm snow .
ECTs showed no propagation potential (ECTX x2) within our 100 cm test depth, though the 1/11 rain crust (pictured below) which is now around 3’ (90cm-100cm) below surface, was visible and collapsed with easy shears.
The brittle 1/11 rain crust layer is <1cm in thickness, made up of 1-2 mm clustered melt forms, with flattened, decomposing stellars both in sub and super stratum, though hard to distinguish.
We did not dig down to observe the 1/4 near surface facet/buried surface hoar layer or the 12/1 melt-freeze crust/facet sandwich.
Center Ridge Meadows, 1,200', N Aspect, 20° Slope, 12:30

Photos & Video
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