Researchers are introducing an extension of the Saffir-Simpson Hurricane Wind Scale, the system used by the National Hurricane Center to rank the strength of hurricanes, to include a sixth category, beyond the Category 5 classification that indicates a storm with sustained winds of 157 mph or more, according to a study published in the Proceedings of the National Academy of Sciences on Monday.

In a new study, published Monday in Proceedings of the National Academy of Sciences, researchers found that the scale, which was created in the early 1970s and is still used to define hurricane categories, has a "weakness": tops out at Category 5 even though "the destructive potential of the wind increases exponentially."