Beats me. I just don't associate weather that is often dark, wet, and cold with 
.
That's one way to look at snowfall, yes. But the idea of the song, White Christmas, and my vision of such a day, is different. It invokes positive feelings of purity, happiness, and unity. You wouldn't dream of it if it was a negative thing, then it'd be a nightmare, and it certainly isn't negative. As such, on that level, I feel light is an appropriate element.
If I'm honest, I'd prefer the card was light with a water ability, but I accidentally clicked on another submission and noticed that was taken, so I swapped them. I still believe it works quite well.
