Date of Observation: 02/19/2017
Name: Zach Guy
Aspect: North East, East, South East, South, South West
Elevation: 9,000-13,000 ft.
Avalanches: No new avalanches. Some cracking/storm slabs 2″ thick on the 2/17 near surface facet layer on NE aspects NTL; completely harmless but an indicator of how fragile that layer is right now.
See photos of older avalanches that ran during last storm or during the warm-up. Glide avalanches, persistent slabs, wet loose, and wet slabs.
Weather: Scattered clouds increased to overcast by late morning; S1 to S3 began around 12:30 p.m, about 2″ accumulation by late afternoon. Light SW winds with light snow transport at ridgeline. Mild temps.
Snowpack: Thick, supportive, frozen crusts on southerly slopes and no avalanche concerns on these aspects. Dry snow still on northerly aspects. The freshly buried 2/17 near surface facet layer was more pronounced/widespread on northerly near and below treeline slopes. Wind battered ATL here. Didn’t see obvious signs of facets around the crusts on southerly slopes, except where the crusts were thin on low angle slopes. 3 pits on northeast aspects were as follows:
1) 10,500 ft. Thin melt-freeze crust about a foot deep, with 1mm facets below. Not reactive under current load (ECTN M) but something to keep an eye on. Near surface facets 1″ deep.
2). 10,700 ft. 1/19 Surface hoar layer was 90 cm deep under a 1F slab. Propagating results in ECT with 4 additional shoulder hits beyond normal loading steps (ECTP 34, SC). Near surface facets 2″ deep.
3.) 12,900 ft. A layer of small grained, well bonded facets was buried 45 cm deep. No fractures in a CT on any layers