Climate & Hurricanes: Future Storms in the Carolinas, Part Two

Hurricanes of the future will challenge the Carolinas, inevitably costing lives and wrecking property, just as they have for centuries. The fact that their winds, tides and rains will be enhanced by climate change is a real concern. But there are arguably other factors to consider that will have a far greater influence on the scale of property damages and human losses we should expect from hurricanes in the decades ahead.

The biggest factors: population growth and our communities’ ability to adapt and become more resilient to the hurricane threat.

Powerful hurricanes swept the Carolinas through the colonial period, wrecking fleets and destroying coastal settlements. As potent as they might have been, similar storms today have a far greater impact on people and communities. In simple terms, steady population growth has put more people and property in harm’s way, and today North and South Carolina each rank among the nation’s fastest growing states. 

Population growth in U.S. is greatest near the shore; the Carolinas are no exception. That trend is expected to continue, as popular vacation destinations such as Hilton Head, Myrtle Beach, Wrightsville Beach, and the Outer Banks attract more year-round residents, and surrounding communities fill with retirees and supporting workers. Higher populations at the coast practically guarantee escalating property damages during future hurricane strikes, partly due to the sheer number of people and structures. The growth of wealth also plays a role—today’s homes, cars and boats are far more costly than those of just a few decades ago.

The Tar River swallowed whole communities in the days following Hurricane Floyd, forcing many onto their roofs. Members of this Pactolus family could only reach their home by boat. (Photo by Dave Gately; courtesy of FEMA)

Our greatest vulnerabilities may lie farther inland, across the Carolinas’ broad coastal plain. These mostly-rural counties are growing too, and they’re crisscrossed by rivers and streams that have already proven lethal and destructive when hurricane rains push them beyond their banks. More populous inland counties near Raleigh, Greensboro, Charlotte and Columbia are vulnerable too, each suffering through destructive hurricane floods in recent years.

At more than $24 billion, 2018’s Hurricane Florence was the Carolina’s most costly hurricane disaster. Though widespread, its greatest flooding impact was in these inland areas. Continued growth brings urbanization, as forests and farmlands are converted for streets and structures—often inhibiting natural runoff and enhancing flooding risk.

The growth trend will continue. In 2019, South Carolina’s Floodwater Commission reported that by 2100, 5.8 million acres of the state’s urban and suburban land will have been developed, a 305 percent increase over developed areas in 2010. North Carolina expects similar steady growth.

That growth will have a positive economic influence that will be welcomed by most. But with it will come the responsibility of managing the what, where, when, and how of land development. Community leaders across the Carolinas, at the federal, state and local levels will be challenged to plan for what future storms will deliver. Revised land use plans, building codes, and other regulations will be needed to help minimize the vulnerability of new development projects.

Gavin Smith, professor at NC State University’s College of Design, teaches classes focused on natural hazards, disasters, and climate change adaptation. He sees a future where local leaders can do a lot to mitigate the impact of future hurricanes.

“In many cases communities have designed themselves, I would argue, in ways that reflect the climate of the past,” says Smith. “Creating more resilient communities is all about good governance . . . Local governments have within their toolkits a whole slew of land-use tools and techniques they can employ to reduce risks . . . They can make choices about where and how building should take place . . . But we find that after the disasters it’s not about the tools they possess; it’s also about the political will to take action. Sometimes that’s difficult to achieve in the aftermath of a disaster.”

In years to come, this will be the challenge: how can communities most vulnerable to hurricane floods become more resilient? Experts in the field contend that effective resiliency takes many forms and is not limited to physical projects like flood gates and seawalls. Communities large and small are now exploring what it means to be hurricane resilient, learning how to protect the environment and enhance their economic and social capacities while planning for growth and the necessary physical improvements that come with it.

And in preparing for that future, we can look to the past to be reminded of what kinds of threats to expect. For most, it will again be rising water. Carolina residents would be wise to remember these truisms from our experience with Hurricane Florence: “Just because it’s never flooded before doesn’t mean it can’t” and “If it’s flooded before, it will flood again!”

This post originally appeared on uncpressblog.org

Climate & Hurricanes: Future Storms in the Carolinas, Part One

No matter where you get your news, it’s likely you’ve seen a recent uptick in the number of stories about climate. In 2021, historic wildfires, killer heat domes, widespread tornado outbreaks, and deadly urban flooding disasters made headlines, and 2022 is turning out to be no different. Earth’s seven hottest years have all occurred since 2014, and the connection between that heat and our worst weather disasters seems obvious. Scientists around the globe are on the case, offering new research in ever-more startling detail about the consequences of a warming planet and what to expect in the years to come.

The threat of more devastating hurricanes is often presented as one of the most serious climate-related perils we face. After his Oscar-winning documentary An Inconvenient Truth was released in 2006, Vice President Al Gore famously said, “What changed in the United States with Hurricane Katrina was a feeling that we have entered a period of consequences.” Since that time, climate change and its influence on tropical cyclones have remained in the news. More recently, some pundits and advocates for climate action have put forward the idea that epic hurricane disasters such as Sandy, Harvey, and Florence were the result of global warming.

From a historian’s perspective, that thinking seems flawed. Big, powerful, and destructive hurricanes are nothing new. The Carolinas have always been a hotspot, with Hazel, Hugo, Fran, Floyd, Matthew and Florence just some of the familiar names. Dozens of other big storms have battered the Carolinas for centuries, most unnamed and relatively unknown. North Carolina ranks fourth in the U.S. for hurricane landfalls since 1851; South Carolina ranks fifth (Florida, unsurprisingly, is first).

A closer look at the science reveals some unexpected ideas about what future hurricanes might be like in the U.S. Researchers use an array of ever-more-sophisticated computer forecast models, run out over decades, which factor increasing amounts of carbon dioxide, methane, and other greenhouse gasses to simulate conditions for future hurricane development.

Chris Landsea, chief of the Tropical Analysis and Forecast Branch of the National Hurricane Center, confirms one finding that may come as a surprise: it’s unlikely warming oceans will generate more storms, as the number of tropical cyclones is expected to remain the same or even decrease due to increased dry air and wind shear in tropical regions. Landsea says the highest category storms, the cat 4 and cat 5 hurricanes that do the most damage, may increase in number. But even if the number of storms doesn’t increase, the status quo is nothing to celebrate—each Atlantic hurricane season could still average fourteen named storms and seven hurricanes for decades to come.

And future hurricanes will be stronger, but only moderately so: “We’re looking at 3 to 5 percent stronger [storms] by the end of this century,” says Landsea. “So as an example, a 100 mph hurricane [today] might be a 105 mph hurricane at the end of the century because of global warming.” That’s a fairly small increase in strength, offering slightly more destructive potential, especially for those hurricanes where wind and tide are the primary factors.

It’s mostly been hurricane rainfall, though, that has swamped the Carolinas in recent years and caused ruin for so many. Record floods in central South Carolina in 2015 were followed by more devastating floods in the Carolinas during Hurricane Matthew in 2016—only to be topped by those of Hurricane Florence in 2018. Florence was poised to strike near Wilmington as a category 4, but it weakened and slowed as it made landfall, dumping record rains across a broad area. After the storm, 59 deaths and more than $24 billion in losses were reported in the Carolinas—making Florence the costliest hurricane in the history of either state.

Search and rescue teams from across the Carolinas and from other states were deployed throughout flooded communities during Hurricane Matthew. This team from Missouri plans their next move on a flooded Lumberton, N.C. street. (Photo courtesy of FEMA)

Future storms will bring more record-breaking floods. Researchers are focusing on how climatic changes might slow tropical cyclone movement and produce stronger blocking weather patterns, yielding more rain. In 2019, researchers at the University of North Carolina at Chapel Hill published a study of high-precipitation events in North Carolina since 1898. They found that six of the seven greatest totals occurred in the last twenty years. Three of those: Floyd, Matthew and Florence. The authors concluded that “…either North Carolina has been very unlucky, or the historical record used to define storm statistics is no longer representative of the present climate regime.”

So, we might expect future hurricane seasons to have roughly the same storm frequency, but those storms that do strike will pack slightly stronger winds and be even bigger rainmakers. Across the Carolinas, inland floods will again sink homes and businesses, and homeowners—especially those without flood insurance—will again suffer dearly.

At the coast, residents will wrestle with another unavoidable consequence—rising sea levels, which over time will enhance any arriving hurricane’s destructive potential. Global ocean levels have been rising about one inch per decade over the last century, but the rate of increase is accelerating—alarmingly so—with the fear that as more polar ice melts, ocean levels could rise two or three inches per decade. “It doesn’t sound like much, but in areas where the terrain is pretty low-lying, even a foot over several decades is a big deal,” says Steve Pfaff, warning coordination meteorologist for the National Weather Service in Wilmington. “Places that don’t have much elevation, that are less than a few feet above sea level, are the ones at risk for having more flooding, more often.”

Hurricanes of the future will challenge the Carolinas, claiming untold lives and property, just as they have for centuries. The fact that their winds and rains will be enhanced by climate change is a real concern, and coastal areas grappling with sea level rise will become increasingly vulnerable. But it’s helpful to keep these changes in perspective, as there are arguably other factors—unrelated to climate—that will have far greater influence on the impact of future hurricane disasters in the Carolinas.

Read part two to learn about other factors and their impacts.

This post originally appeared on uncpressblog.org

What Was North Carolina’s Greatest Hurricane?

Hurricane Hazel destruction in Southport, North Carolina
A woman climbs through debris surrounding the remains of Harrelson’s Grocery on the riverfront in Southport after Hurricane Hazel. (Photo by Art Newton; courtesy of Punk Spencer)

It’s one of the most common questions I hear from readers: “What was North Carolina’s worst hurricane?”

Some think it’s Hazel. Others talk about Fran or Floyd. Usually, they pause to wait for a one-word response—but it’s not quite that simple.

It’s just human nature to want to compare one storm with another, but choosing the greatest? The truth is, the answer depends on what measuring stick is used and over what period of time comparisons are made.

Meteorologists focus on storm track and intensity, and their measurements define hurricanes by extremes in wind, tide, rainfall, and barometric pressure. Pressure readings are particularly important—the lower the barometer, the more powerful the storm. Meteorologists use the Saffir-Simpson scale to rate intensity, categorizing hurricanes from 1 to 5. Thankfully, North Carolina hasn’t experienced a Cat 5, at least not since reliable recordkeeping began in the mid-1800s.

Hurricanes can also be ranked by the dollar damages they bring to communities they strike. Homes, businesses, boats, vehicles, public infrastructure, crops, livestock, and timber are vulnerable to powerful hurricane winds, extreme coastal storm surge, and devastating freshwater flooding. And hurricanes tracking inland (like Fran and Floyd) are often even more costly.

Sadly, it’s also important to acknowledge the heavy toll hurricanes claim in lost lives. While property losses have risen exponentially, hurricane-related deaths in the U.S have trended downward. Though fatalities have generally declined, recent mega-storms Katrina (1,200 deaths) and Sandy (285 deaths) remind us how deadly modern, urban hurricanes can sometimes be.

So yes, we could rank North Carolina’s greatest hurricanes by intensity, dollars, or deaths—but how do we compare modern disasters with earlier hurricanes, when meteorological details are less known and impacts undocumented?

Our hurricane record begins with the first European explorers. Early hurricanes sank ships, destroyed coastal villages, flattened crops, and left untold destruction across the state. But when compared with modern hurricanes, early storms largely impacted sparsely populated areas and caused far fewer damages.

Could the state’s greatest hurricane have swept ashore centuries ago? Perhaps.

Maybe it was the massive hurricane of September 1846 that crept slowly over Pamlico Sound, opening two new inlets on the Outer Banks within 24 hours (Hatteras Inlet and Oregon Inlet). Or perhaps it was the storm that swamped Wrightsville Beach on a full moon tide in September 1856, destroying large stands of live oak that once covered the island. Another contender was the violent September 1883 hurricane that struck the same region, claiming 53 lives along the lower Cape Fear—the most of any storm to that date.

You get the idea. There are lots of possibilities.

5. Great Flood of 1916

Sometimes known as the Great Asheville Flood, this one’s not well known but easily deserves a place on this list. Like Hurricane Hugo that razed Charlotte in 1989, it’s another epic Tar Heel disaster caused by a hurricane making landfall elsewhere. It was two storms actually—one on the Mississippi coast and the second near Charleston days later. Both systems dissipated over the Appalachians, establishing a new U.S. 24-hour rainfall record near Asheville on July 16: 22.22 inches.

Flooding along the Swannanoa and French Broad Rivers was unprecedented. Homes slid down mountain slopes. Mudslides washed away railroad trestles, stranding hundreds of passengers. Estimates vary, but the flood claimed as many as 80 lives, ranking it among the deadliest of all North Carolina disasters.

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Hurricanes and Politics

Florida's Hurricane History, 2nd edition, by Jay Barnes

Thus far, Tropical Storm Issac has captured significant attention this hurricane season, as the first storm to show potential for threatening the U.S. with hurricane force. Of course, a lot remains to be seen about its forecast track, and particularly how much energy it can muster after dragging across Haiti and Cuba before heading our way. It’s early, and the news media in particular wants to get in front of the story, but at this point Issac could end up as an uneventful rainmaker across southwest Florida and perhaps a category-one hurricane on the panhandle coast.

It’s not likely to be an epic event in our hurricane history, though as all hurricane aficionados will tell you, even tropical storms or category-ones can be deadly and destructive. Just ask anyone from eastern North Carolina through New England who suffered heavy damages from Hurricane Irene last year.

Tropical Storm Isaac, 5pm Friday 082412, NOAA graphic

Tropical Storm Isaac, 5pm Friday 082412, NOAA graphic

Much of the news coverage for Issac has focused on Tampa, host city for the Republican National Convention set to get underway on Monday. There’s good reason to focus attention on Tampa too, because along with the entire Tampa Bay area, it is the U.S. city most vulnerable to a major hurricane.

What? Not New Orleans? Well, for a variety of reasons, Tampa has more at stake. It has a considerably larger metropolitan population, a more challenging evacuation situation, and a complacent citizenry that has never experienced a direct hit from a hurricane in its collective lifetime.

In late summer 1935, Tampa was embroiled in perhaps its greatest period of political turmoil. Continue reading