Ulbo means errupt; burst or burst out.
Sample:1) Daling miulbo ang kalayo sa nahitabong sunog kaganinang udto (Fire quickly burst out earlier this morning)
2) Ulbo akong kaspa sa iyang gipanulti sa akoa (I’m freaking out of what she said about me)
This is little bit of a Cebuano figurative language, miulbo ang kaspa!