Hurricane Dorian is the storm that just won’t go away. After leaving a horrific trail of destruction in the Bahamas over the weekend, the storm has meandered to the northwest where it’s starting to cause rapidly deteriorating conditions in the Carolinas and Georgia where “life-threatening” storm surge and “increasingly likely” flash floods are possible into the weekend.
On Wednesday night, Dorian re-intensified to a Category 3 storm before dipping back to a Category 2 storm as of late Thursday morning. Charleston and other parts of South Carolina, as well as Georgia, have already registered tropical-storm-force winds as high as 70 mph and hurricane-force winds are likely later on Thursday. Dorian is expected to remain just offshore through Thursday, its eye within miles of the South Carolina coast. The National Hurricane Center’s (NHC) forecast cone of probability shows the storm could come ashore in North Carolina on Friday.
But while the intensity of the storm and whether it makes landfall are easy to fixate on, the biggest impacts will largely be from storm surge and rain. Tropical storm force winds extend up to 195 miles out from Dorian’s core. As they wrap around the eye of the storm, they’ll drag water across the ocean and send it toward the coast.
The NHC is calling for up to 8 feet of storm surge to inundate parts of South Carolina. In North Carolina, surge could reach as high as 7 feet as Dorian’s winds wrap around its eye and push water ashore. Earlier this week, the U.S. Geological Survey said a region from Florida to North Carolina could see “significant” beach erosion caused by the storm. More worrisome, the Post and Courier reported that it appears transformers are blowing up as waves come crashing ashore in Charleston. The paper noted that more than 200,000 power outages have been reported, and the number could rise as Dorian’s impacts intensify. Officials in Charleston also reported “dozens of road closures” due to flooding according to the local National Weather Service office.
Rainfall is also a huge concern with Dorian as the storm’s bands wrap inland. So far, the highest reported totals are around 7 inches with more rain to come. But a widespread area along the coast could see 6 to 12 inches of rain while some pockets could get in excess of 15 inches, according to NHC. The rainfall alone is enough to raise the risk of flash floods as it runs off into creeks and rivers.
Add in the storm surge coming in from the ocean and the runoff trying to go out to sea and you have a recipe for what’s called compound flooding. The Carolinas are all too familiar with compound flooding after last year’s Hurricane Florence. And while Dorian won’t be on the level of Florence, the next few days will still require vigilance if you live in the area. That means watching water levels in local creeks and streams and not driving across flooded roadways.
While scientists have done attribution work on whether Dorian is caused by climate change, there are clear linkages. Heavier downpours and higher storm surge are two of the hallmarks of climate change. The atmosphere can hold more water while sea-level rise allows storm surge to penetrate further inland.
As the Carolinas stare down the storm, it’s also important to remember the legacy it left behind in the Bahamas. Entire islands were reshaped by the storm at its peak, leaving behind a humanitarian emergency as well as an ecological one. The Southeast states in its path may need help in the coming days, but Lifehacker already has a handy guide for how you can help relief efforts in the Bahamas.