Change Needed To Hurricane Classifications

September 16, 2018

Each time a hurricane makes landfall, it’s a sure bet that rescuers have to retrieve someone who defies an evacuation order. Friday in North Carolina, for example, more than 200 people were marooned after declining to leave their residences as Hurricane Florence roared ashore. In some cases, people simply believe they can withstand the onslaught, despite comedian Ron White’s adept observation that “it’s not that the wind is blowing, it’s what the wind is blowing.” But in other cases, the hurricane classification system might make it seem that storms are less dangerous than they are. Hurricanes are classified on the Saffir-Simpson Hurricane Wind Scale. As its name suggests, the scale considers only a storm’s wind speed, even though that is only one aspect of a hurricane’s destructive power. As Florence moved toward shore last week, it rapidly changed from a Category 4 storm, with sustained wind speeds of 130 to 156 mph, to a Category 1 storm, with sustained wind speeds of 74 to 95 mph. Even though 95 mph winds are sufficient enough to ruin your day, the decline in classification might have led some residents to believe that the storm had become less dangerous. The greatest dangers from Florence, and from many hurricanes, is epic amounts of rainfall that produce freshwater flooding and storm surges that inundate coastal areas. Although hurricanes are described by their wind speed, that calculation does not describe the speed of the storm itself. While producing high winds, hurricanes often plod along at only 5 to 10 mph. Florence has been unusually slow, accounting for the massive amounts of rain it has dumped over a limited area. To better warn the public of a storm’s danger, the National Oceanic and Atmospheric Administration should develop a rating system that accounts not just for wind speed, but for potential rainfall, tidal conditions and other factors that comprise a storm’s overall danger. Some people still would defy evacuation orders, but a new system would make it less likely that people would misread a classification downgrade as a danger downgrade.

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