There has never really been a satisfactory explanation as to how the Lord's "anger" worked as it is described in the Bible.
Religion unites us in times of trouble, it helps us persevere in difficult circumstances, and it gives us hope. But we need to go further and seriously ask, does God use nature to punish?
You might think that if someone is powerful enough, say ... omnipotent, then anger would be unnecessary. And yet it makes a lot of sense that we humans would expect God to get angry.