Avalanche: Hatcher Pass

Location: Stairstep

Route & General Observations

Toured up Stairstep on a mission to find buried surface hoar, observe recent wind effect, and get some good turns in. Southerlies had a 3-4″ thick softened sun crust and northerlies had low density slow pow. We remotely triggered two small wind slabs at 3800′ on NW aspects.

Avalanche Details
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Trigger SkierRemote Trigger Yes
Avalanche Type Hard SlabAspect Northwest
Elevation 3800ftSlope Angle 38deg
Crown Depth 18inWidth 40ft
Vertical Run 100ft  
Avalanche Details

As we got above 3500' it was obvious that the past 10 hrs of wind was enough to build significant wind slabs 6" to 18" thick near ridgeline on leeward aspects on the Arkose ridgeline (always sees more wind than IM bowl). We walked up the ridge and remotely triggered a small D1. We intentionally remotely triggered another similar size avalanche. Both failed on radiation recrystallization crystals within old snow. See pic

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)?Yes
Observer Comments

No cracking collapsing or recent avalanches below 3500'.
Recent small wind slabs at NW 3800'+ that we remotely triggered which also produced long shooting cracks up the ridgeline - see pic
Cooler daytime temps limited natural wet loose activity today.

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

1-2" new snow overnight at 3550'
Calm to light winds
Overcast/cloudy skies in the morning and sunny in the afternoon
2700' 34 deg at 12pm
3550' 29deg at 12pm
4500' 22deg at 12pm
Felt significantly cooler today than the past couple days.

Snow surface

Sun crust on southerlies below 3500'
NSF on northerlies with supportable base - boot pen 35 cm, ski pen 10 cm
Stiff wind slab on ridgelines above 3800' on W to N aspects


Our goal was to look at upper layer instabilities, ie find BSH. We did not dig more than a a couple feet deep.

HS 240cm @ 3000' NW
0-20 F DF
20-35 4F rounds
35-37 I crust (Feb 26)
no buried surface hoar (BSH) observed at this elevation

HS 285cm @ 3500' W
2-3mm BSH found 45 cm down
BSH was non reactive in this location

Photos & Video
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