Verified answer

暴力的 is used for someone who is likely to actually hit someone else. Because 暴力 is act of hitting or harming others.

凶暴 is used to describe violent beast. So you use it to describe someone like a beast, including having mentality like beast.

There are some differences.

We use neither of them on storm, and others.

Very interesting question and I referred to the dictionary.

Daijirin says:

暴力的: a state of violence. an act to settle the issue by the violence.

http://www.excite.co.jp/dictionary/japanese/?searc...

凶暴: a bad, brutal and furious nature. an atrocious and violent act or affair.

http://www.excite.co.jp/dictionary/japanese/?searc...

For examples, google is always useful. Please refer to the words following "凶暴な" or "暴力的な":

"凶暴な":

https://www.google.co.jp/webhp?complete=0#hl=ja&co...

"暴力的な"

https://www.google.co.jp/webhp?complete=0#hl=ja&co...

My conclustion? Both words refer to the violence, but "暴力的" is used for the intentional, purposeful violence as the instrument for certain goal. Imagine a dictator and his means to oppress the people by his violent instrument.

On the other hand, "凶暴" represents the uncontollable bad nature which a reason fails to rule. That is beast-oriented nature. At this point, I partly agree to thecheapest902.

And the applications:

For anything related to the act of human, you can use both "凶暴" and "暴力的". Just google it to add any word you like after "凶暴な" or "暴力的な" ("な"　is suffix to qualify the following word).

Unfortunately the storm is not well "sophisticated" enough as human being, so better to take only "凶暴".

https://www.google.co.jp/webhp?complete=0#hl=ja&co...

https://www.google.co.jp/webhp?complete=0#hl=ja&co...