Avalanche: Turnagain

Location: Sunburst

Date:

February 18, 2019 1:00pm

Observer:

A. Johnston-Bloom Professional

Route & General Observations

Standard uptrack to 2900′.
Looking at how well the new snow is bonding to the old snow, observing wind effect, slab depth and character.

Avalanche Details

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Trigger	Skier	Remote Trigger	0
Avalanche Type	Soft Slab	Aspect	Unknown
Elevation	unknown	Slope Angle	unknown
Crown Depth	unknown	Width	unknown
Vertical Run	unknown

Avalanche Details

Avalanche was observed from Sunburst.
Info with photos was reported to CNFAIC this evening.
This was remote triggered by a skier coming down looker’s left of slide about 11am today.

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

Localized cracking, most hand-pits failed on isolation in low density snow that fell on Saturday.

Weather & Snow Characteristics

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

Weather

Broken skies
Light flurries on and off
Easterly winds 5-10 mph with gusts into the 20s
Temps in the 20Fs

Snow surface

3-6" new snow with obvious wind texture

Snowpack

Feeling the snow pole probing and skinning starting at the parking lot felt 'upside down'. Hand pits at lower elevations showed a few inches of more dense snow over a thin layer of low density snow. This was on top of near surface faceted snow on the old melt-freeze crust. The new snow was more drifted as elevation was gained and an the new snow was stuck to a wind crust from the 2/13-14 wind event with near surface faceted snow below. Hand pits were failing on isolation and the snowpack felt hollow in a few spots. There was localized cracking when stepping above skin track or stepping to demolish pit walls but no shooting cracks. There was not enough of a slab to promote propagation. Will be interesting to see how this set-up does with more wind loading or settlement due to warming and radiation.

Pit # 1 @ 2140'
SW aspect
25 degrees
HS: 170 cm
CT 2, CT 5, C6 failing below wind crust 20 cm down, ECTN 6 20 cm down
CT 23 on MLK BSH 60 cm down, PST 75/End on MLK 60 cm down

Pit #2
2900'
W aspect
27 degrees
HS: 210 cm
CT 2 x 2 20 cm down,
MLK bsh 50 cm down.

Photos & Video

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