Observation: NWAC Observer

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Weather Summary

Sky cover was scattered overnight, and winds were calm before dawn. Over the morning, winds increased and became light from the S/SW. Cloud over increased, and the sky was fully overcast by mid morning. Light snowfall (S-1) began at 9:30 am. There was no old snow avalible for transport due to a surface crust.

Avalanche Observation Comments:

No new avalanches observed. Roller balls from 2/3 off of steep terrain on all aspects.

Snowpack Observations

We found a 1-2 cm breakable crust on all aspects near and below treeline today. There were very small pockets of soft snow in sheltered terrain, but it was difficult to link these together for more than a turn or two.

At 4,200 feet on a NW aspect we found the height of snow to be 250-300 cms deep. Beneath the surface crust, we found 40 cm of settling snow from earlier in the week. This snow sits on top of a thin crust. Above this crust there are very small facets (less than 1 mm) and below the crust there are slightly larger facets (1-1.5 mm). These facets appear to be rounding.

Compression tests highlighted the facets above the crust as our primarily layer of concern and produced sudden collaps results that slid smoothly on the crust. Extended column tests did not suggest any propegation. These two results seem to suggest that while these facets are not currently capable of producing avalanches, they could become a problem if we add a new load to the surface.