After a hurricane makes landfall comes the eerie wait for bad news. For Hurricane Helene — now a tropical storm as it barrels toward Nashville — that news came swiftly on Friday morning: at least 4 million are without power after the storm’s Thursday night arrival near Florida’s Big Bend region; more than 20 are dead in three states; and damage estimates are already in the billions of dollars.
But that’s just the news from the coasts.
As Helene is set to illustrate yet again, hurricanes are not just coastal events — especially in the era of our warming climate. The National Weather Service warned towns in the Blue Ridge Mountains of South Carolina and Georgia that Helene will be “one of the most significant weather events” in the region in “the modern era,” while the Appalachians are in store for a “catastrophic, historic flooding disaster” according to AccuWeather’s Chief Meteorologist Jonathan Porter during a briefing with reporters Friday morning. He added for good measure: “This is not the kind of language we use very often.”
Helene’s dangerous inland impacts are precisely what the National Oceanic and Atmospheric Administration sounded the alarm over earlier this year. Ninety percent of hurricane fatalities result from water, and almost 60% of those are freshwater deaths caused by heavy rainfall. Such fatalities often occur hundreds of miles from the shore in flash floods fueled by the warmer atmosphere, which can hold and dispense far more moisture in a short period than would have been possible in the pre-industrial era.
With Helene specifically, “there are going to be communities that are cut off” as bridges are compromised and roadways wash out, Porter said. Especially in mountain communities that might have only one or two ways in and out of town, that kind of rain raises the level of difficulty for any sort of emergency response and can make evacuation impossible. There have already been reports of 12 to 15 inches of rain in some parts of North Carolina.
“This is steep terrain,” Porter said. “When you get rain rates of 2 to 4 inches per hour, that is going to result in very significant flash flooding that can go from a dangerous situation to a life-threatening emergency over the matter of just a few minutes.” Rivers could exceed record levels by tonight, with more than 2 million under flash flood warnings around Raleigh and Fayetteville. Landslides are also a possibility in the mountains, where just 5 inches of rain from a single storm can be enough to trigger a disaster, the National Hurricane Center warned; two interstates near Asheville, North Carolina, are already closed due to slides.
It’s certainly not unheard of for the remnants of tropical storms to pass over the Carolinas and Appalachian Mountains — hurricanes such as Katrina in 2005 and Lee in 2011 were deadly billion-dollar disasters even as far inland as Tennessee. But as storms get bigger and wetter like Helene, “even people who have lived in a community for decades may see water flowing fast and rising rapidly in areas that they’ve never seen flood before,” Porter said.
It’s time to adjust expectations — and preparedness plans — accordingly. Louisiana, Texas, and Florida still stand for “Hurricane Country” in the popular imagination, but the mountain states of the southeast are rapidly joining that list. The National Hurricane Center is already monitoring a new low-pressure area in the Gulf of Mexico — in nearly the exact same spot that birthed Helene.
