Wind loading in Hippy Bowl in afternoon.
Observation: Turnagain
Location: Tincan
Ascended to 2800′ on Tincan and skied the trees. ~4 inches of new snow. Active wind loading of Hippy Bowl in afternoon. Found propagation potential on intact Jan. 21 buried surface hoar (BSH) and facets under a 1 ft pencil hard slab in Common Bowl.
Observer Comments
Weather
Snowing ~1 cm an hour on average until 2 pm when the clouds cleared. The skies cleared with low valley fog in the afternoon.
30s F at valley bottom and 20s at ridgetops
Calm wind below treeline, light wind above treeline, moderate Northerly wind gusts at ridgetops
Snow surface
3-4 inches of low density snow. The snow did not appear to be bonding that well with easy failures on shovel tilt test.
Snowpack
Below 2100' hand pits failed easily or on isolation on fist hard facets over a decomposing melt freeze crust (MFC) 1.5' to 2' down. The Jan. 21 BSH was present but not failing in hand pits.
Above 2100' tests showed the intact Jan. 21 BSH were reactive, exhibiting propagation potential in Common Bowl under an old pencil hard wind slab. The Jan. 21 BSH lies around a foot down in the snowpack. We did find 1F facets growing around a decomposing 1" melt freeze crust ~1.5' down, but were not getting any failures on this layer.
Noticed a 1" sun crust under the new snow at 1600' on a steep, SW aspect.
Northerly wind transporting snow and loading Hippy Bowl
Propagation on intact Jan. 21 BSH and facets found in Common Bowl under a 1 foot thick 1F hard old wind slab
Intact Jan. 21 BSH found in Common Bowl below previously wind affected snow
Handpits at 1200', 1627', and 2000' failed on isolation or easily on 4F facets over decomposing MFC
Found intact 1/21 BSH and facets and New Years BSH laid over in a snow pit at 2100'
Common Bowl. Wind effect along the ridge was still visible under the new snow.
The clouds clearing after the snow
Sun crust found on steep SW aspect at 1600'