Quick report
- Cracking
- widespread
- Collapsing
- widespread
The touchiest snowpack I have yet to experience this season here. I collapsed near every slope I walked on, accompanied by very loud collapses and often times air bursts with snow coming out from the snowpack.
Weather
- Cloud Cover
- broken
- Wind Loading
- moderate
- Rain Elevation
- 6800'
- Recent Snowfall
- 20-30
- Snow Avail For Transport
- large amounts
Light intermittent precipitation persisted through the daylight hours, becoming moderate (S2) just after sunset. Winds were light increasing to moderate out of the south. Precipitation fell as snow above 6800'.
Snowpack
Leaving the truck near 6100' just before noon, snow surfaces were moist and saturated. Climbing from 6100' to 6400', coverage was thin both on north and south sides of ridgelines. Cracking and collapsing were widespread even in thinly covered areas where brush was still sticking out from the snowpack, indicating a well-preserved weak layer even on exposed terrain at the lower end of mid-elevations. From 6400' to 7300' on an exposed ridgeline, there was 12-15cm of fresh snow overlying a series of semi-supportable crusts, with this increasing to 20-25cm from 7300'-8400', and 25-30cm above 8400' in sheltered locations.
Widespread would not suffice to describe the cracking and collapsing I experienced, particularly above 8500'. I experienced cracking and collapsing almost every other step — the only reprieve I recieved was when I was walking on a panel of snow I had already collapsed. Collapses would travel over 500' away from me and out of sight, several times causing air and snow to spray upwards from the snowpack as the collapses radiated out from my skis. Near 8800' on a NNW aspect, I began remotely triggering avalanches from a safe uphill track on a ridgeline. I remotely triggered one D3 that ran near valley bottom and created a large powder cloud, as well as 3 other D2's that spanned multiple bowls. One of these D2's spanned two bowls and then sympathetically released another D2 in a separate bowl. These were triggered hundreds to close to a quarter mile away on a ridgeline.
Navigating around gendarme-like features towards the summit of Johnstone, I found little slab presence on the solar side of the ridge up to 9100'. Above 9100, the slab was soft and overlying about 15cm of facets and crusts. Nearing the summit, I found many pockets of wind-drifted snow, setting off several small D1 wind slabs.
On my descent, I found a thin eggshell-like rain crust below 6800', with valley fog below 6700'. Surface hoar was already beginning to form at this elevation and below as I exited to my truck.
Avalanche
- Size
- D2.5 R3
- Count
- 5
- Aspect
- NE
- Trigger
- AS
- Elevation
- 9080 ft
I remotely triggered one D3 that ran near valley bottom, as well as 3 other D2's that spanned multiple bowls. One of these D2's spanned two bowls and then sympathetically released another D2 in a separate bowl. These were triggered hundreds to close to a quarter mile away on a ridgeline.