Firm Snow and Improving Strength on on Lincoln Ridge

We wanted to get more data about how the buried surface hoar layer is changing. So we returned to Lincoln Ridge where we had observed signs of instability including unstable snowpit tests and large shooting cracks on that layer on Tuesday. We skinned up to the previous pit location. In most places, we traveled on very firm snow and almost needed ski crampons to ascend the low angle slope to the pit location. Once we stepped off our skis, we could easily post hole through the surface crust. We could see large grains of buried surface hoar in our snowpit about 8 inches below the surface near a melt-freeze crust. Snowpit tests targeting that layer did not yield unstable results today (ECTN x 2, PST 60/100 END). We did try another test where we added an artificial slab on top of the snow surface. This test indicated that fractures might be able to travel through the buried surface hoar if it gets enough new loading on top of it (Artificially Loaded {10cm Slab} PST 30/100 END). 

By the time we finished with this pit around 11 am, the snow surface had started to soften some and we could skin up to the ridge. Once on the ridge, we encountered very firm snow. We chose to step out of our skis and post hole over to the old wind slab avalanche that had caused shooting cracks to propagate along the surface hoar layer. Tests in this area also did not show unstable results on the surface hoar (ECTN). The shallow (6 in) surface wind slab still had not fully bonded to the snow below it, though.

We post holed back to our skis and side slipped down the firm snow to a sunny spot on a low angle ENE slope. In this area, the snow surface had softened enough for decent skiing conditions. However, anytime we crossed into the shade or onto a more northerly facing slope we found either firm icy conditions or breakable crusts.