Dial it up to Category 6? As warming stokes storms, some want a bigger hurricane category

A handful of super powerful tropical storms in the last decade and the prospect of more to come has a couple of experts proposing a new category of whopper hurricanes: Category 6.

Studies have shown that the strongest tropical storms are getting more intense because of climate change. So the traditional five-category Saffir-Simpson scale, developed more than 50 years ago, may not show the true power of the most muscular storms, two climate scientists suggest in a Monday study in the Proceedings of the National Academy of Sciences. They propose a sixth category for storms with winds that exceed...