The act of banking on not having school because of a snowy forecast. At the very least this will usually consist of doing absolutely no work for the next day. Other options include: staying up later than usual, playing in the victory snow, staying at someone else's house, drinking, and other various activities. This glorious activity can be carried out by both students and teachers. The less snow called for, the more exciting the snow banking is.
Disclaimer: Snow banking can only truly occur if the snow banker has no knowledge of an actual snow day yet
Derek: How is that paper coming along that's due tomorrow?
Cam: I'm not working on it, I'm over at Conor's
Derek: How will you get it done before tomorrow then?
Cam: It doesn't matter. They're calling for a half inch of snow overnight. I'm snow banking. Hard.
the act of fucking in a snow bank
"Me and that girl were wasted and we started snow banking"