Cirque Forepeak avalanche

Avalanche

Run Length

450

Slab Width

25

Trigger Type

skier

Wind Exposure

leeSlope

Avalanche Size

2.5

Slab Thickness

30

Trigger Sub Type

accidental

Start Zone Aspect

S

Trigger Distance

10

Vegetation Cover

openSlope

Start Zone Incline

45

Avalanche Character

windSlab, deepPersistentSlab

Crust Near Weak Layer

1

Number Of Avalanches

2-5

Start Zone Elevation

2770

Runout Zone Elevation

2320

Avalanche Observation

12hrsAgo

Weak Layer Crystal Type

depthHoar, facets

Start Zone Elevation Band

alp

Avalanche Occurrence Datetime

2024-02-13T18:00:00.000Z

While traversing on top of a narrow alpine ridge feature a member of our party triggered a sz. 2-2.5 avalanche that ran roughly 400-500m downslope, with a crown that varied between 10-60cm and had a propagation width of roughly 25m. We then pushed a bit further and intentionally triggered a second slightly smaller avalanche on the adjacent feature. Needless to say the snow was touchy in this steep and rocky terrain. Both avalanches initiated on what looked to be the late Dec. melt freeze-sun crust layer just off the ground and then stepped down in spots to scrub the ground where the well preserved depth hoar was located. It is suspected that this feature has previously released and reloaded given the limited snow depths in a lee feature. Snow depth in thinner spots near the ridge consisted of roughly a 5cm windslab overtop 10cm facets, with a 5cm melt-freeze crust on top of 10cm of depth hoar. The perfect avalanche recipe when mixed with steep terrain! Lower on the route between 2300-2700m we also observed shooting cracks and whumpfing in lower angled and wind affected terrain.