Jawbone Canyon

The main theme of the day was that so little melt occurred today that a late start and late return did not affect the efficiency of travel on the descent until below 9000'. Ambient air temperature was below freezing at the trailhead at noon and clouds rolled in and slowed solar warming by 2:30 PM. 

BTL: Surface snow from three days ago was still unconsolidated and dry on NW, N, NE aspects in Jawbone Canyon at noon, but had crusted over below 9000' on all aspects by the time we left the field.  Snow coverage is patchy below 9000'. The combination of a dry winter, windward scouring and sun has left little coverage on S, SW, W except in cross-loaded features that accumlate wind drifted snow. Where there is coverage low down exposed or shallowly buried objects are a hazard to riders in this area. On a NW aspect at 9000', HS: 0 -100 cm, Boot Pen 20cm, Ski Pen 5cm. Surface is either melt freeze or a dusting of bry precip particles - supportable to skis less so for boots.

NTL: NE 10600': Ski pen 20cm in recent dry powder snow. Boot pen 40cm through weak melt-freeze crusts. HS 180cm Early season basal weak layer down 160cm under a very strong mid-pack. West scoured to old crusty sastrugi and melt-freeze. E pillowed, but with sun an temperature crusts. NE, N , NW loose snow becoming moist, or remaining dry and loose depending on sun exposure. In isolated areas, a thin wind slab shears easily, but will no propagate or send cracks beyond ski tips. These spots tend to be in the transition from wind scoured to wind deposited terrain features. If they did relate to the wind slab problem the likely size would be 1 to max 1.5 and stubborn to trigger.