Originally Posted by bizznessman
: To be used in place of 'well', when one feels there is no more to say. This word was originally brought to the peoples' attention in 1994, from Jim Carrey in the cult classic, Dumb & Dumber.
This is simply one of the many words and phrases that continue to be used in teen conversation today.
I am not sure where it originated, but my family is from Tennessee and we always say "Welp" when we are prepping to leave someone's home or end a phone call. "Welp, I'll see ya'll later."