Come to think of it, I think I “wooo” a little myself. Mostly while watching hockey games, because what else am I going to shout? “Yeah” just seems too manly, somehow.
Give ululating a try!
I did that on Sunday when the Cowboys were ahead. But then I was WOOOing again when the Seahawks won. 
I usually WOO HOO. Definitely both syllables. I don’t think I’ve ever shortened it to just WOO. But I’m formal in that way, I guess. 
It’s better than YIPEEE, don’t you think?
Tally Ho!
Do female college students in … oh, Instanbul, wander the streets shouting LALALALALALALA! at random?
And as DSotF recalls; guys say WOOOOOOO too: