After devastating the Bahamas earlier this week, Hurricane Dorian—which has diminished to a Category 2 storm—is now poised to batter swaths of the American Southeast.
Though it’s still unclear if Dorian will make landfall in the United States, its trajectory, which parallels the coast, still threatens residents of Georgia and the Carolinas with destructive winds, violent rains, and powerful storm surges, beginning as early as this evening. Florida, which is now creeping into the storm’s rearview mirror, remains at risk of flooding, particularly in the northeastern part of the state.
On Sunday, Dorian swept ashore in the Bahamas as a Category 5 storm. It then spent three days tearing through the archipelago’s northern islands with wind gusts around 200 miles per hour and bringing a 23-foot storm surge. The hurricane’s excruciatingly slow march over the region left Grand Bahama Island in its eyewall—the most intense part of the storm—for 40 hours.
With these staggering statistics, Dorian ties the Labor Day hurricane of 1935 for the strongest Atlantic hurricane to make landfall and holds the title for the most powerful storm to hit the Bahamas directly.
“What we saw in the Bahamas is unprecedented,” says Ángel Adames-Corraliza, a climate scientist and tropical meteorologist at the University of Michigan. “As far as we know, we’ve never had such a powerful hurricane just stall over an island...the term ‘catastrophic’ falls short.”
Though tropical storm warnings were finally discontinued by the Bahamas’ government this morning, the potential for further flooding and tornadoes lingers. At least seven fatalities have been reported, but the death toll is expected to rise as officials continue to tabulate the destruction.
On Tuesday, Dorian finally resumed its slow march north. Now newly downgraded to Category 2, the storm has been leached of some of its mojo, but it’s also expanded in size, says Marshall Shepherd, a meteorologist and weather and climate expert at the University of Georgia. That means its winds—the worst of which still clock in around 100 miles per hour—could batter a broader region.
Crawling northeast at about 9 miles per hour, Dorian is predicted to shudder through Georgia and the Carolinas over the next day and a half, likely prompting flooding and coastal erosion as far north as Virginia, Shepherd says. The place at most risk of the storm coming ashore is probably the Outer Banks region of North Carolina, he says.
Regardless of whether it makes landfall, Dorian will make much less of an impact in the United States than it did in the Bahamas. That said, “it is important for people not to minimize the risks,” says Suzana Camargo, a climate scientist at Columbia University’s Lamont-Doherty Earth Observatory.
“This is certainly a hazard for people on the coast...anyone from north Florida to Virginia should be paying attention,” Shepherd adds. In preparation, hundreds of thousands have already evacuated several counties that line the southeastern shores.
Coasts are expected to be relatively clear by Saturday morning, with a well-weakened Dorian drifting well off the shores of the Northeast United States.
Original forecasts had Dorian making landfall in Florida on Monday, but the storm abruptly altered its path over the weekend. Hurricanes are moved by steering flows—large-scale wind patterns in the atmosphere that dictate storms’ trajectories like currents tugging canoes downstream. But these flows can shift depending on a wide range of atmospheric conditions, Camargo says.
Flows could also help explain Dorian’s stop-and-go trek, Adames-Corraliza says. Near the Bahamas, it seems Dorian got stuck in a sort of steering flow dead zone that stalled its movements.
On the whole, though, Dorian was forecasted well—enough to confidently preempt several evacuations in Florida, for instance, Shepherd says. “In some ways, this story exhibits just how impressive...today’s models are,” he says.
Individual storms are difficult to pinpoint as anomalies, Shepherd says. After all, September is hurricane season. But as the climate continues to change, storms may become more extreme.
As global temperatures climb, the atmosphere’s capacity to hold water vapor increases, potentially boosting the amount of rainfall storms bring to a given region. Hurricanes are seeded by interactions between balmy water and air—and as the seas warm and swell, storms could become more energetic, while storm surges plunge further inland. There’s even some evidence that broad-scale alterations in our planet’s climate could increase the number of Dorian-style standstills.
These patterns of intensification may have already peeked through in startling ways, Adames-Corraliza says. Dorian’s attainment of Category 5 status marked the first time in recorded history—since the start of the satellite era in the mid-1900s—that the tropical Atlantic has experienced storms of this caliber four years in a row. “That’s unusual and worrisome to some degree,” he says. “Just think...there’s a lot to let sink in here.”
To learn more about hurricanes and the future of catastrophic storms, watch “Rise of the Superstorms,” premiering at 9 p.m. EDT/8 p.m. CDT on Wednesday, September 4 on PBS.