| Recent Avalanches? | No |
| Collapsing (Whumphing)? | Yes |
| Cracking (Shooting cracks)? | Yes |
Observation: Turnagain
Location: Seattle Ridge - Sunnyside/Repeat Offender
Standard up-track to the ridge and over to the top of Main Bowl (1st Bowl).
Obvious signs of instability
Observer Comments
Numerous whumpfs above 2300', some seemed to travel 100' or more.
Some shooting cracks where the slab was thin (<12").
Only one small wet loose avalanche noted on Seattle Ridge. Likely from yesterday's warmth. No signs of slab avalanche activity.
Weather
Broken to overcast skies, very light northerly winds, and temps near 30F.
Light snowfall began around 3pm.
Snow surface
Snow surface was moist powder below 2,300' with a sun crust (yes a sun crust!) on east and south aspects. Crust provided for less than inviting turning conditions at the lower elevations...
Above 2,300' soft settled powder and much better turning conditions.
Snowpack
In short: 1-3 foot slab over basal facets. Prior winds have created quite a variable snowpack depth.
The facets (a 1-6" thick layer) at the base of the pack were prevalent above 2000' and it was not until 2300' and above that we noticed the incessant whumpfing. We also found a crust within the faceted layer. It appeared that in areas the crust was thin, whumping was occurring below the crust, where the crust was thick, failure seemed to be above it.
Slab was generally soft snow on top (fist hard), transitioning to harder (1 finger) snow at the bottom just above the faceted layer.
Pit #1 2350', snow depth 100cm
ECTP 17 sudden collapse (video) in facets above the crust
Pit #2 2800', snow depth ~80cm
ECTX, then ECTP 13 sudden collapse in facets above the crust
Facets were around 2mm and striated. We did see some cupped larger facets under the crust at 2800'.
Lower elevation snowpack is without facets and roughly 18-20" deep.
Snowpack at 2800'
Aleph pointing at two layers of facets surrounding a crust
Close up of the facets above the crust, the most reactive layer we found (2mm grid)
Facets below the crust - you can almost see the cupped shaped larger grains
Seattle Ridge - Zero Bowl
Repeat Offender slide path looking from near the bottom of the valley (20" moist snow at this 1100' elevation)
Looker's left side of Repeat Offender path
A sun crust capped the snowpack on south and east aspects below 2300....