Lee Vining Peak

We had a full-value Sierra spring day, with minimal Sierra spring skiing. We worked our way up barren S faces with our skis on our backs. We found crusts on all aspects with snow coverage below 10,500'. There is moist depth hoar at lower elevations.

Above 10,500', the melt-freeze crust disappeared. We traveled through old wind slabs, faceted wind slabs, and on scoured slopes. We triggered collapses on the PWLs near shallowly buried trigger points, such as rocks and trees, that propagated throughout the slope. The snowpack is dry above this elevation on northerly elevations, and the PWL are very much alive and well. 

Rollerballs and wet slides were observed on solars, but they may have occured any time in the last 48 - 72 hrs. 

We experienced cracking and localized collapsing on the surface-melt freeze crust on all aspects up to 10,500. When stepping out of our skis on low angle slopes, we fell through the crusts and through the weak layers and our feet could touch the ground. Above 10,500, the surface MFcr disappeared, and we were able to initiate cracking and propagation from our skis on the Depth Hoar at the base of the snowpack.

HS varied depending on aspect and elevation. HS 5 cm - 100 cm. Most snow found between 9500' and 11000' on W - N - E aspects. Lower elevation southerlies barren. Various slopes ATL scoured. 

PWLs varied in stability and depth. Slab varied in thickness and hardness. 

9900' NE: HS 65 cm, ECTP25 @ moist depth hoar. Upper snowpack wet above MF crust. Snowpack dry below MF crust, and above DH. 

10200' W: HS 100 cm, too many rocks for an ECT - CT 11 SC @ DH. DH 2 - 4 mm, dry to moist. Upper snowpack consists of: MF crust, F moist rounds, ice lense. Dry snow exists below the ice lense - 4F - 1F slab. 

As we approached 10,500, MF crust grew thinner, and old wind drifts were present and faceted in spots. We began experiencing collapsing and cracking with propagation as we continued to gain elevation on northerly aspects. 

11000' N: see pit below