Green Butte Ridge

Today's objective was to verify expected wind slab instabilities and assess the new snow. In short, it was touchy out there. Signs of instability were obvious across all elevation bands. Wind slabs could be found on easterly aspects near, and above treeline. New snow totaled around seven inches across the mountain, with deeper spots due to wind loading. Winds remained elevated and temperatures were cold through the day.

Observed instabilities were mostly associated with wind transported snow and development of wind slab. The new snow and strong winds have quickly formed wind slabs on easterly aspects below, near, and above treeline. Below treeline, these slabs were specific to leeward terrain features, and were quite reactive to trigger. Shooting cracks and collapsing slopes were easy to find in visibly wind loaded areas. However, most of these slabs were small, and would not carry or bury a person. Near treeline, the amount of wind loading was far more intense. The strengthening winds were quickly moving all available snow onto easterly aspects, all across the slope. Some slabs were up to 2 feet deep, over double the amount of snow that has recently fallen. Above treeline, exposed slopes appeared completely stripped of all new snow. Instability was also found in a pit dug at 8,300 on a southeast aspect. On a compression test, failure occurred on isolation (CTV), collapsing on a soft snow interface (below Dec. 30 crust) 18 inches down from the surface. Upon extended column test, this same layer failed and propagated on tap 14 (ECTP14). Shear quality was Q2, showing resistant fracture characteristics. This weak interface appears to be low risk and low likelihood to trigger, but It's something to note.