As far as I understand all the theory I have sucked up to get throught that bloody IR exam on Monday, in order to get icing you need to have super cooled water droplet (not knowing it should be ice) freezing on impact on your wing. The snowflake has been already transformed to ice, from water inside a supersaturated freezing cloud, by growing around a dust particle. So it doesn’t need your wing to freeze up, and even if it is below zero you shouldn’t get ice from snowflakes, simply because both are different physical appearances of water in its solid state. Tell me I’m wrong, please, I need a reason to skip the exam :)
