Quick report
- Cracking
- specific
Touchy wind slab above Phantom Trees at base of Snoq S Face. Lots of active wind-loading above 5000'. Epic tree-bombs falling due to wind. Skier taversed slopes above Phantom Trees at the base of Snoq S Face (5200') on skins to investigate stability (1:30pm). Progressively steeper test slopes were traversed. The slope that failed was a convex roll beneath a rock rib (local low pressure zone) with maximum slope angle ~45deg. Crack propagated from ski No other instabilities observed in Phantom Trees area. Weather was intermittently very windy, clear, or snowing heavily. Skin track was refilled by wind on each successive lap to the top of Phantom Trees. Later in the day (~3pm) cracking of the top layer of snow was easily observed when stepping above the established skin track.
Snowpack
Hand pits on lower angled terrain at base of Snoqualmie Mtn S Face demonstrated a clean interface 12" deep that was likely the sliding surface for the triggered wind slab.
Avalanche
- Size
- D2
- Aspect
- SW
- Trigger
- AS
- Elevation
- 5200 ft
Wind slab ~12" deep at highest point. Crack propagated ~30ft across local convex roll. Slab slid downhill away from skier 50ft to local concavity.