Broken Top

Toured up Broken Tops S Ridge with a plan of potentially riding the SW face aka Thunderbird. I was interested to see if some of the facet layers and persistent weak layers existed on south aspects and to monitor them in the alpine in general after all the snow we’ve had in the past two weeks. At 7600ft on the ridge I experienced a whumph and collapse of the snowpack. I immediately dug a pit and performed an ECT. Results were ECT 15, a sudden collapse propagated all the way across the column. The snowpack failed on a crust facet sandwich with the upper crust being the the one from January 13th I believe. After digging the pit I continued up the ridge line and experienced another whumph just a couple hundred feet higher. Then near the top of the sw face on the ridge line at 8800 feet I continued to be observe weak sugary snow underneath a thick rime and water ice crust widespread on the ridge and extending into the tops of the chutes and gully’s of the sw face. I performed a couple more hasty pits at the tops of the gully’s getting as close to the meat of the lines as I comfortably could. ECT’s were propagating and releasing upon isolation of the thick crust that sits on top of wide spread weak faceted snow. I then decided to turn around and ride the ridge line back to the lower angled mellower terrain. My impression is that weak faceted snow underlies the snowpack even on south aspects. The whumphs I experienced was on shallower more scoured parts of the snow pack but I would assume those layers exist in the middle of the bowls and chutes where the snowpack is deeper and one is less likely to experience a collapse or whumph but the snow was definitely reactive in my tests on the shallower edges and the whumphs show that one could potentially trigger a deeper slab if you hit the right trigger point . There was enough uncertainty in the strength of the snow to avoid more complex and consequential terrain.

Broken Top

Quick report

Avalanche