Professional Observation

Observation Details

Signs of Unstable Snow

Key Points

Today we made a quick tour in the Mammoth backcountry to evaluate the wind slab problem near treeline.

• We found wind deposited snow on all aspects near treeline with wind scouring at ridges due to SW winds during the last storm and a strong subsequent NE wind event. Wind deposits were 20-25cm deep on top of settled snow from earlier in the storm.
• In isolated areas on NW aspects near treeline we saw cracking in the wind slab under our skis on test slopes.
• We had repeatable propagating results down 20-25cm in the ECT on test slopes adjaent to cracking.
• High clouds and cool temerastures limited the influence of solar warming. While the snow surface did become moist during the day on steep S and SE slopes, little to no evidence of wet snow instability was observed