Traveled between 3,200ft and 6,900ft generally on north to east facing terrain. Between 5,800ft and 6,200ft while skinning through the trees we experienced roughly 7 whumphs, with a couple of those propagating and initiating more whumphs. They collapsed roughly 30ft sections of snow, shaking the snow out of some trees. These are the types of instabilities that would be avalanches if the slope were steep enough to slide. Twice I was able to collapse the slope even after 3 to 5 people had skinned by, just by jumping up and down a few times. Collapsing was confined in nature given that it was only this relatively small elevation band, though widespread within that band.
Below is a summary of the layer of concern (Early December Crust and associated weak snow above and below) found through different elevations.
At 4,200ft NE aspect HS 143cm, Early December Crust found down 80cm as a thin, freezing rain crust. CTM (11) SC x2 on .5-1mm rounding facets below the crust. Much of the snow beneath this crust was moist, rounding facets.
At 5,100ft on an ENE aspect, found HS 135cm, and a thinner freezing rain crust was down 75cm.
At 5,800ft on NE aspect found HS 135cm. The layer of concern was down 75cm. CTM (11) SC on .5mm rounding facets above the Early December Crust PST 35/100(End) test was done on the small facets above the crust, but fractured through crust, and ran to the end on rounding facets below the crust.
At 6,200ft on NNE found HS 139cm, layer of concern down 70cm. CTH brk down 49cm on storm interface. CTH SC (within crust, down 1cm) down 69cm. PST 30/100 (End) on 1-1.5mm rounding facets within the crust.