Rapid wind-loading
Collapsing in the open slopes between 800-1200'
Cracking on wind-loaded convexities
Observation: Turnagain
Location: Eddies
Standard route until popping out of the trees around 800′ and then headed to the north across lower open slopes and skinned up through the trees to 2300′.
Observer Comments
Weather
Obscured skies
Light to moderate snowfall throughout the day 2-3" of accumulation, raining at sea level
Sustained NE winds 15-25 mph with stronger gusts
34°F at parking lot. Mid 20°Fs at upper elevations
Snow surface
2-3" of new snow becoming 4-5" by end of tour - heavier snow on lighter snow in the low elevation terrain below 600'sticky
In wind exposed terrain 2-3" wind crust trending to 6-8" slab
Along ridge above 2000' it is scoured to previous wind hardened snow and there is small sastrugi
Ski pen was really variable from 2-8" to no ski pen in wind affected areas
Snowpack
We dug at 1200' just before heading into the trees. HS 355 cm, pit depth 100 cm. See photo. The 2.9 facets were 35 cm down and propagated ECTP4 in both pits. Compression tests were failing underneath the 1.23 melt-freeze crust in small facets but no propagation on this layer.
We dug again at 2000' in a slightly wind loaded area. HS: Over probe depth probing from bottom of pit depth (100 cm). See photo. Both the 2.9 layer and the 1.28 layers were obvious but there was no results on the 2.9 layer. The 1.28 layer was intact buried surface hoar 8-12 mm. We both had propagation on this layer, ECTP23. Besides the soft surface snow the slab above the bsh was 1F to Pencil hard and the snow below was Pencil hard.
Take homes for the day...
Wind slabs were building and triggering a buried weak layer remains a possibility.
Pit @ 1200'
ECTP2 and ECTP4 @ 1200'
Steady snowfall and wind transport throughout the day
Pit @ 2000'
ECTP23 @ 2000'
Cracking on a wind-loaded convexity