Culross Island

Quick report

Collapsing

isolated

Route: Goose Bay up to 1350' on Culross Island, from ~1 - 4:30 PM. Weather: WARM - felt above freezing throughout the day, with strong sun. Generally calm at Culross, with occasional light east winds. Scattered thin clouds for most of the day; thicker clouds coming in from the south by evening. Red flags/signs of instability: One very prominent collapse when two of us grouped up right next to each other at what turned into our high point (1350') for the day. This collapse propagated 100+ feet around the small terrain feature we were standing on, with a slight visual drop of the snowpack. As this collapse was at a similar aspect and elevation to a slab further south on Culross Island, we stopped here and dug pits! While the location of the snowpit had already collapsed, CT tests failed again with a sudden collapse fracture character after 8 and 9 taps, down 35 cm at the bottom of a layer of 1-1.5mm rounding facets at the interface of firmer old snow. The ECT did not propagate but failed at 10 taps, while a PST failed at 40/100 END... an unstable result. Full structure and test results are below. As we travelled up, we noticed that the snowpack in the top 2 feet dried out fairly substantially with just a short amount of elevation rise to this location... winter snowpack conditions definitely still exist out on the sound! Additionally, some recent D1 wet loose along the route originating at rocks or trees; despite the surface being wet, we had trouble initiating anything on small W aspect rollovers. Snow Surface: Near sea level at midday the snow surface was generally supportable in the trees, but it was starting to fall apart and go isothermal by late afternoon. Above 500' on west aspects, a thin layer of large wet grains sat on supportable surfaces for our ski down, though ski pole probing revealed a solid foot of wet grains under a thin supportable layer from 500 to ~1000' on west aspects. When the upper snowpack was supportable, ski penetration was 1-2". Snowpack: Not much of a snowpack down low; just a foot or so along the coast of Goose Bay, but this increased with elevation... probing around 600' in elevation revealed 150-200cm, and note the 275cm depth of the pit at 1350'.

Avalanche

Some isolated recent wet loose activity on steep solar aspects, or on small terrain features with trees/rocks as a starting point. Slab avalanches from last week... none observed beyond what was reported on 4/9 by Graham. See photos below!