What is the word for people who have bursts of anger?

I would say just to stay away form that person.Don't talk or hang around them.If it's a sibling, then try telling them how you feel about it.

AnswerSomeone that's acts out in bursts of anger would be short tempered if they do so at minor provocation, if theres no provocation though then it would be something else (possibly a mental health issue.)

volcanic - explosively violent