Overcast skies led to obscured as we ascended and a wave of moderate snowfall came in that lasted through the afternoon. E winds transported snow in moderate amounts in exposed areas.
Dec 11, 2021
Rock Mountain lower gully
A number of the steep SE facing gullies ran naturally as D2 soft slabs, estimated on morning of Saturday 12/11. See associated avalanche occurrence.
HS was measured at a few different elevations/locations:
The hardness profile is generally favorable with F snow on the surface in most areas outside of recent wind effect down to 1F+ or so above the crust from December 8. This crust presents as a translucent freezing rain crust and is consistently 3-5mm thick, and down 90cm-120cm from the surface. We found small grained (0.5-1mm) rounded facets above and sometimes below it. We targeted this layer for some tests at 5,300ft on E, 6,200ft on SE, and 6,200ft on NE.
We got consistent Sudden Planer results with Compression Tests (CTH) on 1mm rounded facets above the crust at the 5,300ft site.
The other sites revealed no results on this layer, but did receive Resistent Planer failures (CTM) 50cm down on a density change on the SE aspect at 6,200ft.
Comments: Small, shallow wind slabs forming on exposed slopes due to E winds.