While we were descending the Lower East Mineral ridge line a soft wind slab pulled out sympathetically, 40 feet below a ski cut. The weak layer was at the old/new snow interface. Not sure of the exact culprit, but the new snow was inverted and not well bonded in multiple hand pits dug while ascending. The crown varied between 5" and 10" and approximately 80 feet wide running a couple hundred feet into the trees below. Winds were moderate with intermittent snow squalls. Good turns were had up top but the snow was warm and heavy below 8000 feet.