Recent storm, considerable storm slab problem downgraded to moderate today. Weather was 19 at Narada falls, clear skies in the morning fog/clouds and snow intermittently throughout the day. No major signs of wind loading, small lip formation on N ridges showed no reactivity even stomped on. Traveled up to Castle Peak on the north facing slope, skied backside of Pinnacle south facing slope into Butler Basin, skinned back up to Plumber peak and skied the NE facing slope at Pinnacle saddle. No instability or slab features noted, but weather noted to become more humid at that time (about 12:30 pm), and snow seemed to become more dense compared to very dry fluffy powder noted all day prior. Skier entered slope, made 4 turns and large propagating cracks appeared at a roll over terrain feature. Skier was above majority of avalanche, carried about 100 feet and completely unburied. Avalanche propagated across most of the slope and ran all the way down the gully. No one was physically injured. Skiers exited terrain safely.