Swift creek avalanche

Incident

gkingsford ยท Feb 23, 2021

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Weather

Wind Speed
windSpeedStrong
Blowing Snow
moderate
Sky Condition
brokenClouds
Wind Direction
W
New Snow24 Hours
10
Storm Start Date
2021-02-22T14:39:00.000Z
Storm Snow Amount
30
Temperature Trend
steady
Precipitation Type
none

Snowpack

Obs Type
summary
Site Aspect
S
Site Elevation
2100
Ski Penetration
15
Site Elevation Band
tln
Surface Conditions
newSnow
Whumpfing Observed
1

Avalanche

Run Length
500
Slab Width
250
Trigger Type
skier
Wind Exposure
crossLoadedSlope
Avalanche Size
3
Slab Thickness
50
Trigger Sub Type
accidental
Start Zone Aspect
S
Vegetation Cover
sparseTrees
Start Zone Incline
35
Avalanche Character
windSlab
Number Of Avalanches
1
Start Zone Elevation
2200
Runout Zone Elevation
1850
Avalanche Observation
12to24hrsAgo
Weak Layer Crystal Type
stormSnow
Start Zone Elevation Band
tln
Avalanche Occurrence Datetime
2021-02-23T02:45:00

Settlement occurred after the party of three had skied the slope. Transitioned to skinning and proceeded up slope for second run. Initial settlement was observed and discussed as a group. Immediately after a much larger settlement the propagated up slope triggering entire slope.

Incident

Group Size
3
Terrain Trap
trees, gullyDepression
Group Activity
skiing
Number Involved
1
Number Fully Buried
1
Terrain Shape Trigger Point
convex

Party travelled up trees on the west side of slope. Circled around to top of slope to avoid a concerning area of wind loading. At start of slope, skiers descended one at a time and regrouped near the base of the slope below an outcrop of trees. Transitioned to skinning and started an up track over existing ski tracks. Group discussed possible terrain trap to the east. Second person felt a settlement and notified party. Shortly after a much larger settlement occurred and triggered a wind loaded section at ridge line. This triggered remaining slope. All parties were caught in the ensuing avalanche. Two members had avalanche airbags and deployed them during the slide. One member came to rest face down, head down but was able to clear their face and remove their backpack to initiate SOS. self extricated and initiated beacon search. Travelled upslope and found second member face up, head down and partially buried. Assisted in their extrication and continued beacon search for third missing group member. Unable to obtain signal and believe SOS device was negatively affecting search function (intermittent signal found and chased from 70m to 20m before lost, numerous times). Search and rescue arrived on scene at 5pm.