Hurricane Irma, battering the Caribbean and threatening to make landfall in Florida in the coming days, is by one measure already a record-setting storm. Even storms that reach the same status on the Saffir–Simpson hurricane wind category scale can have much different results. Hurricane Katrina and Hurricane Rita each achieved Category 5 status — wind speeds of at least 249 km/h — three weeks apart in 2005 and were comparable when measuring top wind speed and barometric air pressure. Their Cyclone Damage Potential index (CDP) looks not just at peak wind speed, but hurricane size and forward wind speed. Bracing for hurricane Irma in Florida5:31Matthew was the first Category 5 Atlantic hurricane in nearly a decade when its effects were felt in September and October 2016.

Source: CBC News September 07, 2017 09:00 UTC