Some people are convinced God caused the recent tornadoes. I don't share that conviction. God certainly is sovereign, but that doesn't mean He is the cause of everything that happens. For example, God did not cause Lucifer to sin and rebel in heaven; nor did God cause Adam and Eve to sin. There are plenty of destructive things which happen and yet were not caused by God.
We must be careful not to "blame" God for something that is a part of our fallen world. While it is true that God did cause some disasters in the Old Testament, we do not have conclusive biblical evidence to make a dogmatic statement about every single hurricane and tornado that happens in the world today. To make such a dogmatic statement is to assume to know the mind of God in each of those instances.
This faulty line of reasoning is similar to when people say that a Christian is being disciplined by God every time something painful happens in their life. You simply cannot make such a blanket statement and have any biblical footing for such a generalization. Take Job for example. We are told "this man was blameless and upright; he feared God and shunned evil." (Job 1:1) Yet look at what the Lord allowed to happen to him. Job had not sinned against God in some way that was leading the Lord to discipline him.
It is interesting how the story of Job not only gives us insights concerning painful things happening to believers, but it also sheds much light on this issue of tornadoes as well. There was a very strong wind in Job 1 that caused death and destruction and that wind came from somewhere.
In Job 1:12, the Lord said to Satan, "Very well, then, everything he has is in your power, but on the man himself do not lay a finger." It was only seven verses later "when suddenly a mighty wind swept in from the desert and struck the four corners of the house." (Job 1:19) The house then collapsed on Job's sons and daughters and they were killed.
Does Satan have the power to cause such a "mighty wind" if God allows him to do it? Apparently so. This text certainly gives no hint that God commanded or caused the mighty wind to sweep in so suddenly. Since God is always sovereign over everything including the weather, He certainly allowed it to happen. But that is not the same thing as commanding it or causing it to happen.
So did God cause the recent tornado outbreak? We don't know what factors in the spiritual world, if any, produced the tornadoes. We know God allowed it, just like He allowed Adam and Eve to choose evil....but that doesn't mean God caused evil....or that God causes every storm.
God sent the flood in Noah's day. The Bible addresses that one very clearly. He caused that flood in that situation to happen. Beyond the examples in Scripture, the Bible does not address every single tornado, or every single illness, or every single job loss, etc.
We live in a fallen world. Painful things happen. We don't always know why. On this side of heaven, we need to be careful not to try to have an answer for every "Why?" It can lead a person to speak for God about a matter that is clearly unknown to us in our present state.
Interestingly, I find that those who believe God causes every tornado and hurricane tend to be the same people who believe in "double predestination." They believe God predestines many people to go to hell....and this decision by God is made before those people are even born. They believe that since God didn't stop the tornadoes and since He doesn't prevent people from going to hell, He must therefore be the cause of such things. That train of thought fits with human reason, but you won't find biblical proof for it in the Scriptures.
On the topic of heaven and hell, the Bible is clear that Jesus died for all sinners and that "God wants all men to be saved." (1 Timothy 2:4) There is not even one Scripture passage which states that Jesus died only for believers. God is not the cause of people going to hell. Man's sin and unbelief is the cause.
At the end of the day, we don't know everything there is to know about the cause of each tornado. Having access to complete knowledge of how spiritual forces interact with weather patterns is a bit above our pay grade. What we do know is that Jesus went through the horrible pain of the cross in order to save us. That we know for sure. That is the message God wants us to share with others. Jesus died for every sinner who died last week in those tornadoes, as well as every sinner who survived. As far as trying to nail down the spiritual cause of tornadoes, what advantage is there in trying to pin that one on God?