Weakening Snow on Mt Blackmore

Dave and I toured into Blackmore basin today and skinned up the SE shoulder to the ridge. As we entered the basin, we immediately noticed several natural loose snow avalanches (R1 D1) in steep rocky sections of the direct E face. These looked to have occurred in the last 24 hours, and though they would not have buried someone, they would have strained one through some nasty trees and cliffs.

Gaining the ridge, we could see there had been previous windloading on both sides of the ridge. Cornice formation showed winds from the N/NW but, dropping onto the N shoulder showed evidence of windloading from the E/SE also. We dug two snowpits: one on the N shoulder and one on the E face. Varying snow depths ranged from 50-70cm and up to 90 cm in wind-loaded spots.

Our snowpits showed us two things: our snowpack is showing signs of early season faceting and our areas of most concern are wind-loaded slopes where there is a slab on top of that weak snow. In our snowpit on the E face, we got propagation at ECTP 16 at the interface between wind-blown snow and faceted grains. With this upcoming bout of high pressure, we will be continuing to dig down and see how the snowpack is changing under our feet.