Late Winter or Early Spring snow is usually what gives way in avalanches so you really Don't want to be skiing or snowboarding "completely alone" with no one to dig you out in an emergency especially in the back country where they don't have "snow cannons" to bring the avalanches down when people aren't skiing at night. Alone in the backcountry with too much new snow in drifts from blizzards is the most dangerous. It is sort of like "Snow Jenga" in a sense. You don't know when it is going to come down. You could whistle or talk to someone and the next moment be under 10 to 20 feet of snow avalanche and never heard from again until the summer (maybe at the earliest if you are alone).
You only have to get caught in an avalanche like I did and fight for your life to stay on top of it like I did in the 1980s to understand the real problem of Avalanches is they are often NOT survivable if you are alone going through this. Even I was up to my neck in snow with my shirt off on mountaineering skis having thought I was going to be thrown into tall trees and be killed by the speed I was moving down the mountain on top of the avalanche when it suddenly stopped so I didn't die. I was all alone. It cured me completely of skiing alone above Tree line on Mt. Shasta or anywhere else for that matter in the late winter or early spring when Avalanches happen without any warning the most.
I had no warning at all just all of a sudden the acre of snow I was skiing on was moving down the mountain at great speed and I had to try to stay on top so I wouldn't suffocate and I barely survived with no shirt on in the cold snow with only my head sticking out. I had to really struggle to kick my skis above the then very loose and unstable snow surrounding me but by moving slowly (after I dug myself out up to my neck) and packing down each step with my mountaineering skis once I got above the snow I was able to traverse this "quicksand like" snow from being so loose after an avalanche by packing down each step several times to get out past the acre of snow that had gone from around 10,000 feet to around 8000 feet elevation with me riding it trying to stay alive by staying on top of it as it traveled.
Today's snow conditions