Monday had perfect bluebird, calm, sunny ascent up Chickadee with 10+cm fresh, dry, light powder. Clouds started arriving 1pm. Descended off col towards Boom Lake. Cornice at col easily traversed. Descent through large well covered sags in upper glacier. Then skiers right to steeper descent through calf deep powder. Large cornices above. Visibility deteriorating. Navigated through cliff and steep sections to bench where we found a short section of wind slab. Sluff off of Boom. Snow started as we descended towards Boom Lake and then up to col back to Chickadee. First descent gully had previous powder turns. We elected to traverse to 2nd gully which had slid and was crusty (likely previous solar) and bulletproof avalanche debris. Scratched 100m or so and then elected to traverse further to next gully which had 10cm powder near bottom.