93N Bow Lake and Surrounding Area
The Thompson Rivers University ski tour program 3 has been travelling along the 93N corridor over the last couple days. Tours have taken us up Mt. Olive , Cirque Peak (N. Couloir, exit cirque/observation sub peak drainage), and Observation sub peak circuit. Travel has been smooth albeit a little chilly; the forecasted new snow and warmer temperatures are welcomed. Below are observations based on Feb 28th day tours and snowpack tests done March 1st:
Snowpack summary (2017-03-01):
3 cm overnight has contributed to a 15-20 cm, low-density surface. This is overlaying a variable quality midpack: The alpine is well consolidated and supportive with good bridging over basal weakness. In treeline and below treeline it is less supportive and varies largely in thickness, also overlaying basal weakness.
Observation note: Field team (March 1) travelled to an alpine bowl feature in the north Crowfoot Glades zone as well as the southern part of Helen Shoulder. In Crowfoot we backed off a convex feature to access the bowl due to building windslab (5-25 cm, 1F) that was reactive and cracking underfoot.
The past days we observed some older avalanches along the 93N corridor. Primarily SW aspect plus a cornice fail trigger (old 48+hours) on the Cirque glacier. No new avalanches observed last two days but there was some sluffing off steep, un-skiable terrain due to wind transport.
Snowpack test summary:
Windslab in lee features is quite reactive underfoot and releases while isolating the block (CTV).
Tree line feature (SW aspect) had a very weak base that yielded full propagation on ECT test, down 92cm on large facets and depth hoar (130HS). Given our tests in conjunction with the bulletin we have elected to stick to conservative, well supported terrain and keeping overhead hazard on our mind. We also noted windslab as a problem in the alpine and treeline.
Moving into the next couple days we are planning to step back our mindset, given increase in precip and strong winds.
On behalf of TRU Ski Tour 3
Instructors: Jordy Shepherd MG, Shaun King MG, Deryl Kelly SG