Question

What does Macbeth say can set loose these storms

Answer 1

Macbeth said that an evil act can set loose to the storms. He realized that one murder can let to another. He sees himself as drenched in blood which he thinks he can never get rid off or go back from. He resorts to defeat that the only way for him to live his life is in evil. So...yeah. That happened :/
I hope this helped :D