Hellfire, not too sure this is a haiku in the strict sense of the word. Haiku are poems of observation, and I can hardly imagine the observation of a snowman "jumping". Perhaps a winter animal? Also, I think you can find a synonym for "jump" that could replace "jump for joy" with one word. Never mind the syllable count (as long as you keep it under seventeen) for a haiku in English language, it should have less syllables than in Japanese.
I hope this helps.
Mark
·······  ·······
|