Made famous by a boy in NC with some form of Tourette's syndrome, this affliction is manifested by outbursts in a variety of situations. The phrase has been adopted by others not diagnosed with Tourette's and is yelled out during good times, indicating elation. This ranges from just having had mind blowing sex, receiving a raise, or finding out that some evil bastard has gotten his punishment at last.
Jim just got a promotion. Whoo! Terry Bradshaw!
That bastard just got fired! His evil reign has come to an end! Whoo! Terry Bradshaw!
Wow! That girl is fine as hell! Whoo! Terry Bradshaw!
That was the best blow job ever! Whoo! Terry Bradshaw!