BC Zone Observation Report
Monday, December 17, 2012 at 12:00 AM
apron below Y Chute, N side of Hidden Knoll
overcast, moderate snow, blowing snow, 10-20mph westerly wind est, gusting to 30mph est, 15F est, 0F wind chill est
20cm-40cm HST, extremely variable coverage, poor base, small fresh soft storm slabs, lots of exposed rock in the aprons, extensive wind transport, frequent collapsing, frequent Q1 shooting cracks (irregular, spiderweb-like networks), frequent Q1 "D" shaped half-moon cracks around skis. large (3mm+) columnar basal facets, some 6mm+ long, poorly bonded into larger columns, lots of air space that collapsed easily. did not attempt a formal profile. quick ski-pole column failed on isolation in basal facets layer.
AS / r
apron below Y Chute
Average Slope Angle:
Maximum Slope Angle:
O - Within Old Snow
Weak Layer Grain Type:
remotely triggered from below with collapse and shooting cracks from edge of large trees at distance of 250' lateral and 100' vertical. slid slowly with low energy but ran surprisingly far on low-angle apron terrain. toe stopped around 50' from trees and fresh skin track.
pan of full track showing relation to Y Chute and large trees below the apron