Tuckerman Ravine

Today I joined two forecasters from MWAC as an observer and field partner. We skinned up to Tuckerman Ravine to assess the current snowpack after receiving 7” of snow over the past few days. We observed a crown line on the Headwall, and its associated debris pile below which measured about 14-16” deep. The crown looked older, possibly from Tuesday or Wednesday and had begun to refill. Additionally, upon entering the ravine we observed a thicker, new crown on the looker's left side of Right Gully followed by an interaction with the skier who triggered the D1 avalanche from above. They were unharmed. We continued to skin up to an area near the Open Book and dug a snow pit. We performed an ECT which produced no result. The snow surface is firm and chalky throughout the area we observed. Sastrugi was seen higher up in the bowl, and old avalanche debris at the bottom. Small, isolated, smooth pillowy surfaces were observed in wind-protected areas that can and should easily be avoided with good terrain management.

Observed a skier triggered avalanche in Right Gully on a narrow isolated pocket in a wind-protected area.

We dug a pit near the Open Book and observed pencil hard snow 36" thick, followed by 12" of 1F, and 4" of 4F below that to where we did not continue because the depth was well past a meter. 

Overall found generally stable snow conditions, but we discussed the red flag of a recent skier-triggered avalanche.  Overall, the problems are surface, and today were easy to identify with clear conditions. Potential problems, like the avalanche in Right, are on sheltered lee-terrain, steep, and unsupported. This was in contrast to textured and wind-affected snow around it. We found areas that appeared planar (smooth,) were sheltered, and found stubborn to non-responsive firm wind-drifted snow.