storm surge

Hurricane Katrina was one of the most devastating hurricanes in history, leading to over 1800 fatalities and tying Hurricane Harvey as the costliest hurricane on record. But at the time Katrina made landfall, it was “only” ranked as Category 3 by the Saffir-Simpson scale, which goes up to Category 5. So why did Katrina, at only Category 3, cause so much more destruction than most Category 5 storms? And what does that tell us about what the Saffir-Simpson scale is missing?