It's a relatively new expression that means something big and fun is going to happen slowly but surely. It's an updated version of Badabing Badaboom which basically stands for something something accomplished. It's mostly used in "Party" situations.

A close synonym in slang is "Damn Straight"

A Bloomer is someone with a bright outlook on life who is optimistic in nature. Bloomer's frolic in every opportunity to be happy and try to make the most out of life. The opposite of a Bloomer is a Doomer. The term Bloomer originated specifically as a counter to the Doomer on sites especially like 4Chan.