Usually this happens when the ski conditions are crap, its been all rainy and then the slopes get hard and frozen - basically - who wants to ski on that? So we sit around, we sigh, we mope about and eventually some smart ass says - lets go surf.
Unfortunately its not that simple. We have to check the ice shelf below the wave to make sure we won't get killed by washing under it, the ice flow coming down, so we don't get killed by a truck sized block coming down, and of course, have a board available that you don't mind destroying, because you will. But if these conditions are in place, and you don;t have a last minute attack of intelligence, then we will from time to time go out.
This pic for the Mirror was taken at -18C (plus wind chill). It was downright chilly. Don't forget to dress warm!
You can see a video here from another session of ice surfing.