Other things wrong with that code: All the "snowflakes" fall at the same speed. Yuck. It uses a character ("." in your version, "*" in the recommended version) instead of *IMAGES* for the flakes! (If you use real images, they look better and you don't need as many.)
Oh, w.t.h. Let me see if I can find my old snowfall code that looks and works much better.
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.