Close call — I messed up. I triggered a soft slab avalanche in Little Chute at Alta Ski Area. Right before this happened, there was a lack of communication between my partner and me as to where I was going to drop in. I ended up dropping in on the skier's left of the couloir, right on the wind-loaded part. I had intended to ski across to the other side of the chute before making turns but I didn't even make it halfway across when a large slab popped out in front of me incredibly fast. It had a 30-40' fracture line with a crown that was about 12-18" deep. The slab ripped out the entire chute to the ice crust layer underneath and traveled all the way down to the groomed run some 1,000' below. I skied the bed surface of the avalanche to a safe spot below where I reconvened with my partner.