The final tornado that threatens Metropolis is easy to figure out after a few tries. First off when it appears, you have to save about 3 or 4 citizens in various places. Do that first.

Then you have to go and put out a couple of building fires. Try using the SUPER DUPER Breath. One blow will snuff the fires. Then Superman will say something corny -- along the lines of, "I have to try one more time". He'll automatically fly into the tornado and here's where the encounter gets simple.

When the tornado turns blue inside, use your heat vision and when the tornado turns red, use your ice breath.