Crowfoot Couloir (fan)
Banff Yoho & Kootenay National Park
qturner , Sunday 4th April, 2021 10:45AM
Broke a track up the fan of crowfoot couloir this AM. Turned around just shy of the couloir when conditions deteriorated with strong winds & a squall of fresh snow. A recent 10cm thick windslab had ripped mid way up the couloir, entraining loose dry & flushing out the lower half likely early this AM. Our concern was the remaining hangfire. Ski quality good on the fresh debris. Found soft cross loaded wind pockets on the ~E aspect of the fan. New snow has bonded well. Pit near base of fan had a failure at CT21 65cm deep on large grain facets. No propagation/result on ECT.
Snow conditions were: Crusty, Powder. Riding quality was good.
Avalache Conditions: Slab avalanches today or yesterday.
Compression test: resistant planar 65cm down on large grain facets. Extended column: no result. 10cm fresh overlying a 1cm thick crust, well bonded. 30cm down is another 1cm thick crust, melt freeze? Unreactive. 65cm down are large facets, Mar 18? Reactive on CT, no propagation on ECT.
See photo: loose dry from steep alpine ripped a small windslab on a rocky outcropping, producing a size 1. A similar recent avalanche was found in the couloir itself spreading onto the fan. Both about 10cm thick, entraining fresh snow.