| Trigger | Natural | Remote Trigger | Unknown |
| Avalanche Type | Soft Slab | Aspect | Northwest |
| Elevation | 3000ft | Slope Angle | unknown |
| Crown Depth | unknown | Width | 1000ft |
| Vertical Run | unknown |
Avalanche: Girdwood
Location: Crow Creek Area
Went up to Crow Creek to check out conditions after reports of recent avalanche activity. We found a lot of recent avalanches and a very weak snowpack structure.
Avalanche Details
Many avalanches in the area. The largest appeared to be 1000'+ wide and to have released on layer of facets on top of the Thanksgiving crust. Most of the activity was in areas that likely saw recent wind loading on Thursday.
Obvious signs of instability
| Recent Avalanches? | Yes |
| Collapsing (Whumphing)? | Yes |
| Cracking (Shooting cracks)? | No |
Observer Comments
We triggered 3 large collapses in the area where we stopped to dig a pit. Luckily it was low angle and there was no connected terrain above us, otherwise it seemed likely we could have remote triggered an avalanche.
Weather
Valley fog with clear skies above, felt like a temperature inversion. Calm wind where we skied but there was some active wind transport on the high peaks in area in the morning.
Snow surface
The surface snow was faceting out under the clear skies and cold temperatures. There was a new layer of surface hoar on top. Boot penetration was 3'+.
Snowpack
We found about 30cm (12") of decomposing new snow on the surface. Underneath the snowpack was weak but pretty rightside up until a layer of well developed facets about 65 cm deep. These facets were 1-2 mm and sitting on top of a melt freeze crust. We had ECT N's with moderate strength on the storm snow interfaces in the upper snowpack. On the facet layer we had to slam on the shovel after the test (ECT P 32) to get it to go, but it propagated with a sudden collapse once we initiated the failure. We followed up with a propagation saw test (PST 25/100 END), which indicated that the weak layer is reactive and capable of easily propagating a failure.
Two large persistent slab avalanches on Goat Shoulder.
Snowpack structure on a slope across the valley from a large persistent natural avalanche.
1-2mm facets on top of the melt freeze crust.
ECT Propagation on Facted Weak Layer
Evidence of a lot of wind transport on upper elevation slopes.
Several D2 avalanches near Magpie.