Observation: NWAC Forecaster

Advanced Information

Weather Summary

Lightly snowing throughout our tour with limited visibility. Winds were SW in the moderate range at ridgetop. Temperatures stayed in the 20's.

Snowpack Observations

On Friday my partner and went hunting for buried surface hoar and near-surface facets (NSF’s). Leading up to this storm, we observed widespread surface hoar and NSF below and near-treeline. These weak grains formed on Dec 6th after a cold and clear night. Going into the day I was unsure if these grains survived the moderate to strong winds at the start of the storm, but we did in-fact find these grains intact in most areas we dug.

On Friday we observed these weak grains 25 cm (10 inches) below the snow surface. We easily located the thin gray line of surface hoar in most areas we dug at mid and lower elevations. This layer proved touchy in stability tests with columns failing on isolation and shooting cracks apparent in areas it existed. There wasn’t much of a slab over-lying this layer yet, but that will change with forecasted precipitation.

We weren't able to dig in areas above treeline, so we’re unsure if this layer survived at those elevations. In the next few days it will be worth checking its distribution across these higher elevations.

Tests:

5400 ft, E aspect: CTV (failing on isolation) SP, 25 cm down on buried SH.

5800, NE aspect: CT3 SP, 25 cm down on buried SH.

Multiple shovel tilt tests failing with easy force ( 1st tap) .