Touchy Times at Tunnel

Avalanche

Run Length

60

Slab Width

40

Trigger Type

skier

Wind Exposure

leeSlope

Avalanche Size

1.5

Slab Thickness

25

Trigger Sub Type

remote

Start Zone Aspect

NE

Trigger Distance

8

Vegetation Cover

openSlope

Start Zone Incline

30

Avalanche Character

stormSlab

Crust Near Weak Layer

1

Number Of Avalanches

1

Start Zone Elevation

1850

Weak Layer Burial Date

2021-01-29T01:06:00.000Z

Avalanche Observation

12to24hrsAgo

Weak Layer Crystal Type

surfaceHoar

Avalanche Occurrence Datetime

2021-01-29T15:00:00

Cautiously poked a little out onto a suspect slope on a slight bench with the aim of digging a pit to help us decide if we were happy to drop into Mercury Bowl. Having previously dropped a small cornice on a similar slope and only seeing slough running with no slab qualities we felt cautiously confident that we weren’t doing a stupid thing. Somewhat inevitably, stomping as I poked out onto this perfect lee slope (where we had observed surface hoar forming not 7 days ago) my last stomp shot a crack 8-10m which then propagated across the slope. Retreated a little way and dug a pit. With the propagation question answered we did a quick compression test to see how easily it triggered and had a failure at 4 hits from the wrist 25cm down on classic large glassy remnants of surface hoar. There was a further failure at 10 hits from the wrist on what looked like a previous wind slab. Needless to say we subsequently stuck to south aspects and found great turns with limited amounts of loose dry snow moving around with us.