These Areas at Risk in Newly Proposed Category 6 for Hurricanes

With warmer temperatures across the globe each year delivering intensified tropical storms, scientists proposed a new category for the five-point scale classifying hurricanes.

A study published Monday in the Proceedings of the National Academy of Sciences suggested a new Category 6 standard for hurricanes, which would describe storms that reach wind speeds of 192 mph or higher. The current five-point system, known as the Saffir-Simpson scale, ranks any storm with winds 157 mph or above as a Category 5 hurricane.

According to the authors behind the study, James Kossin of the First Street Foundation and Michael Wehner of the Lawrence Berkeley National Laboratory, the most intense tropical storms “are becoming more intense and will continue to do so as the climate continues to warm.”

Kossin and Wehner found that there have been five storms over the past decade that would qualify as a Category 6 hurricane, all of which occurred in the Pacific Ocean. Category 5 storms have also become increasingly common in recent years, and the authors found in their study that the chances of storms potentially reaching a Category 6 intensity have “more than doubled” since 1979.

“I think what we really want to make folks to do is to take any hurricane seriously, regardless of category,” Kelly Godsey, senior service hydrologist and meteorologist at the National Weather Service (NWS) in Tallahassee, Florida, said during a phone call with Newsweek regarding the study published this week.

What Areas Could Be Most Impacted by Category 6 Storms?

According to Godsey, the increasing intensity of hurricanes brings more risks than just higher wind speeds. Tropical storms are also judged on three other categories—storm surge, flooding rain and tornadoes—and Godsey highlighted that “the stronger the storm, in general, the more energy that’s transferred to the ocean,” which can generate powerful storm surges once the system makes landfall.

Areas in the United States that are already particularly vulnerable to storm surges, then, are likely to be hit the hardest by a potential Category 6-level storm, Godsey said. This includes coastal cities in the Gulf of Mexico and up the Eastern coastline, including inland communities in the mid-Atlantic region and New England that may get hit as storms move further inshore.

“Where we’re most densely populated, of course, are where you’re going to have the potential for the greatest loss of life,” Godsey added, recalling the impact of Hurricane Katrina on New Orleans in 2005, or the devastating flooding that hit the New York City metropolitan area in fall 2022, as Tropical Storm Ian made its way inland, even after downgrading from a hurricane.

“I think when we talk about heavy rain … any city is going to be vulnerable to devastating flooding,” the forecaster continued. “The urban areas more so, because when we’re in a densely populated area, obviously there’s more people, but where does that water go?”

Why Add a Category?

Kossin and Wehner’s study published this week adds to the growing discussion about methods weather authorities can utilize to better convey the range of impact from more intense hurricanes.

“You know, the niche of a Category 6 certainly gets people’s attention,” Godsey told Newsweek. “The thing that I would always message back as part of the National Weather Service is that, you know, hurricanes are more than just wind speed.”

Recent climate studies have found that over the past 50 years, nine out of 10 tropical storm-related deaths were due to water impact, as noted in an August 2023 blog post by National Hurricane Center Director Michael Brennan. Storm surge accounted for 49 percent of all deaths directly linked to tropical storms. In comparison, wind-related deaths accounted for one in seven incidents during the same period.

“Water doesn’t necessarily seem threatening,” Godsey said. “But that’s another part, a very crucial part of a hurricane that people seem to discount. And you know, if a storm was getting more intense, yes, it’s going to lead to greater surge.”

The NWS’ message to those faced with a tropical storm, Godsey added, is to “run from the water and hide from the wind.”