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Stephen M. Strader, PhD - Villanova University. Villanova, PA, US

Stephen M. Strader, PhD Stephen M. Strader, PhD

Assistant Professor of Geography and the Environment | College of Liberal Arts and Sciences | Villanova University


Stephen Strader, PhD, is an expert on the interaction of climate change, natural hazards, and society.






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Shrinking of polar ice caps (February 2017) Increased storm damage over the next century (May 2017) The Weather Channel's Geek of the Week (April 2017)



Areas of Expertise (5)

Wildfires Severe Weather Hazards and Society Natural Hazards Geographic Information Systems


Severe weather – tornadoes, hurricanes, hail, wind, blizzards, thunderstorms, floods – cause disruptions to daily life and exact a heavy toll on lives and property. A meteorologist, whose research on tornadoes includes storm chasing in “Tornado Alley” each spring, Dr. Strader is a highly knowledgeable source on all types of severe weather; the effect increasing global temperatures have on the frequency and intensity of storms; as well as the risk and disaster potential of increased population density in storm vulnerable areas. He can also discuss what scientists are working on to improve readiness for and responsiveness to severe weather events.

Education (3)

Northern Illinois University: PhD

Northern Illinois University: MS

Indiana University: BS

Select Accomplishments (2)

Northern Illinois University Sigma Xi graduate student research competition honorable mention (personal)


Northern Illinois University Most Outstanding Master's Thesis Award (personal)


Affiliations (4)

  • American Meteorological Society
  • Association of American Geographers
  • Sigma Xi Scientific Research Society
  • Gamma Theta Upsilon Geography Honor Society

Select Media Appearances (23)

Tornadoes, Floods Clobber US Midwest

Voice of America  radio


Scientists have been studying possible links between climate change and the frequency and ferocity of tornadoes.

Villanova University professor Stephen Strader says it is not yet clear how much influence the warming atmosphere and other changes have on these deadly storms.

In a VOA interview, the extreme weather scientist said, "We're not there from a scientific standpoint, yet." He said it does seem likely, but not certain, that we will see more severe weather of various kinds in the future.

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Hurricane season is early—again

Popular Science  online


With the formation (and subsequent dissipation) of Subtropical Storm Andrea on Monday, 2019’s hurricane season got off to an early start—just like in 2018. And 2017. And 2016. And 2015. That means a record five years in a row have seen a named storm form before June 1, the official start date of Atlantic hurricane season.
Stephen Strader, an assistant professor of geography and the environment at Villanova University, says there are three changes scientists watch for: hurricane season’s length, the intensity of its storms, and the places where those storms occur. All are predicted using models, like those simulations of a storm’s path you see on a weather forecast.

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From space, powerful thunderstorms look like boiling water

Mashable  online


The most potent thunderstorms roil and churn, like a pot of boiling water.

In severe-weather prone places, like the U.S. plains, a calm cloud can rapidly transform into a fuming supercell thunderstorm. That's why, when viewed from space, these storms sometimes appear to burst out of the atmosphere. "On these really violent days we can see a cloud go from a normal cloud to a severe thunderstorm in a matter of 20 minutes," said Stephen Strader, a severe weather expert at Villanova University who chases these storms through the U.S. plains. "Within 30 minutes [the storm] could have a tornado warning."

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A hurricane in the mountains? Natural disasters await far from the coastal storms, and almost no one there is talking about it

The Washington Post  online


What remained of an unnamed hurricane ripped across the mountains and ravines of this dramatic and sheer landscape, home to Appalachian State University, spitting out days of rain … It says something “about our willingness to shoulder risk and take a gamble on building in areas with a history of hazard impact,” said Stephen M. Strader, a professor of geography and environment at Villanova University. “The increasing trend in developed land throughout the U.S. illustrates this time and time again, from wildfires to flooding.”

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For North Carolina, and for the Rest of Us, the Danger Is Rain

Slate  online


In all cases, human development complicates and aggravates the damage. The geographer Stephen Strader at Villanova has concluded that the primary reason we’re seeing a rise in storm damage is because people are moving into storms’ paths. New arrivals are vulnerable themselves, but in many cases they are also worsening the impact on their neighbors as increased density leaves the consequences of impervious development and wetland removal unaddressed. Furthermore, unprotected industrial facilities—like oil and chemical facilities in the Houston Ship Channel or the pig and chicken barns in North Carolina that are now spilling toxic waste as a result of Hurricane Florence—drastically worsen the consequences of flood events. In Madison, the subject is all the more tricky because of political maneuvering around how high to keep lake water levels. (Everyone likes high water for recreation, but it doesn’t leave much room for error when storms come.)

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Trump Keeps Lying about the Deaths of Americans

The New York TImes  online


The latest hurricane. I wrote earlier this week that climate change could be a cause of the rapid intensification of Hurricane Florence. In The Times, Stephen Strader, a professor at Villanova, makes a related point: The growth of urban areas in places like the Carolina coast is increasing the impact of natural disasters. His piece includes a fascinating map that shows how housing density in the Southeast has changed over the past three decades.

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How Can AI Help to Prepare for Floods in a Climate-Changed World?

Scientific American  online


But human activity has intensified disasters in other ways, too. Population has exploded along U.S. coastlines, exposing far more people and infrastructure to related threats. Stephen Strader, an assistant professor of geography and the environment at Villanova University, calls this the “expanding bull’s-eye effect.”
“Societal growth is the biggest influence on disasters because it increases the potential for loss,” Strader says. It also means more of the environment has been paved over by human habitation, changing the hydrology of major floods in ways that are not well measured or communicated.

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Why the Carolinas Have Become More Vulnerable to Hurricanes

The New York Times  online


By Stephen M. Strader
Stephen M. Strader is an assistant professor in Villanova University’s geography and environment department.

Twenty-nine years ago this month, Hurricane Hugo barreled ashore just north of Charleston, S.C., a category 4 storm with maximum winds estimated at 140 miles an hour and the highest storm tide ever recorded on the East Coast.

Here is where people lived in the region in 1990. Hugo was the nation’s costliest hurricane ever at the time, with damages of about $7 billion.

Over the next three decades, an estimated 610,000 homes were added within 50 miles of the coastline, according to my research.

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Mapping the Unequal Burden of Hurricane Florence

City Lab  online


Cameron Beccario is responsible for the Van Gogh of Hurricane Florence maps, created from his map of global weather conditions. While the Category 3 storm barreling toward the Carolinas won’t be pretty, Beccario’s map in all its data visualization glory is perhaps the most elegant depiction of Florence’s potential power … On Twitter, a disaster expert at Villanova University, Stephen Strader, also noted that development can increase vulnerability to disasters for humans and their possessions—a phenomenon called the expanding bull’s-eye effect. “Humans and their possessions are targets of these geophysical hazards like hurricanes and as populations grow and development spreads across the landscape, it creates disaster potential,” Strader told CityLab.

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As Hurricane Florence intensifies, so do challenges forecasting its path

The Philadelphia Inquirer  online


If Hurricane Florence's forecast track holds, it almost certainly will endanger lives, set off devastating floods, destroy coastal properties, yet again inundate the bankrupt National Flood Insurance Program, and redefine the beaches along vulnerable barrier islands … "My biggest fear is that it will stall out," said Stephen Strader, a disaster specialist at Villanova University. Worst-case scenario: a disaster similar to the deadly Texas rainfalls wrung out by Hurricane Harvey after landfall last year.

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Why Hurricane Florence Could Generate Historic Rainfall

Gizmodo  online


It’s not that Florence’s winds aren’t a big deal—they are likely to be extremely dangerous and produce deadly flying debris—but there’s going to be a potentially historic amount of rainfall inland and powerful storm surge along the coast. Together, they’re responsible for 76 percent of all direct hurricane deaths.

“There’s an old saying that those that live near the water will eventually live in the water,” Stephen Strader, a geographer who studies disasters at Villanova, told Earther.

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Hurricane Florence Looks A Lot Like These Past Three Deadly Hurricanes

BuzzFeed News  online


Hurricane history has a dire warning about Hurricane Florence, now a Category 4 storm with sustained winds around 140 mph, aimed right at North Carolina and South Carolina … Villanova University’s Stephen Strader noted more than 11 million homes are now in the cone of the storm’s projected landing zone inland.

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Hurricane Florence Is a Warning of What’s to Come

Rolling Stone  online


We have also built a lot of homes in places that are high-risk for hurricanes and flooding. Stephen Strader, an associate professor of geology at Villanova University, points out the expanding bullseye of developed land in the region now at risk for flooding.

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One Force Driving Deadlier Wildfires? People

NPR's "Science Friday"  radio


While climate change is certainly to blame in fanning the flames of wildfires (by boosting temperatures, parching landscapes, and causing more erratic rainfall) there’s another factor that’s making today’s fires increasingly dangerous: people. Specifically, a nearly 1,400 percent increase in the number of people building homes in harm’s way since the 1940s.
Villanova University’s Stephen Strader published those findings earlier this year in the journal Natural Hazards, and he joins Ira and USGS research scientist Jon Keeley to discuss how humans can cope with deadlier, more destructive wildfires.

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More than 1 million homes planned for high-risk fire areas in California. Should they be built?

Sacramento Bee  online


Not long after she bought her home in the grassy hills of western Stanislaus County, Julie Davis watched as a helicopter filled buckets of water from a nearby pond and attacked a windswept wildfire burning just outside her community … “We’re seeing wildfires that have always been a part of the landscape that are now interacting more and more with us - not just because they are getting larger, but because we’re building in wildfire prone regions,” said Stephen Strader, a researcher and geographer at Villanova University.

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Huge rise of people at risk from wildfires as western US population grows

The Guardian  online


There’s been an enormous increase in the number of people at risk from wildfire in the western US in recent decades, with an estimated 6.7m homes now at significant risk from fires that are getting larger and more frequent.

“It’s a two-headed dragon where we’ve seen an increase in the number of large wildfires and a big increase in population in the worst wildfire areas,” said Stephen Strader, assistant professor of physical and environmental geography at Villanova University and author of the research. “We see everywhere that cities are enlarging, people are spreading out from the urban core.

“In California, this growth is concentrated in areas prone to fire. The west is continuing to grow because of westward migration so this trend is going to continue,” Strader added.

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California Wildfires: It’s a people problem

San Jose Mercury News  online


Even as fires rage across California, thousands of new homes are being built deeper into our flammable foothills and forests, as lethal as they are lovely.

A recent surge in subdivisions in high-risk wildlands is putting more of us in harm’s way, say experts. For millennia, wildfires just burned trees; now they’re claiming homes, with heirlooms, pools, family photos, pets, cars and precious lives.

“It’s the ‘expanding bull’s eye’ effect,” said geographer Stephen M. Strader of Villanova University, who tracks population growth in high-risk areas. “Cities are moving into regions where there were no people before. People and wildfires are coming together more often.”

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Limiting suburban sprawl can ease the devastation of wildfires

Mother Nature Network  online


Published in the journal Natural Hazards, an eye-opening new analysis from Villanova University geographer Stephen M. Strader illustrates how aggressively sprawl has encroached into what Lisa M. Krieger, a science writer for the Mercury News, calls “our flammable foothills and forests.”

Per Strader’s findings, over the past 50 years there has been a 1,000 percent increase in the number of homes in the western United States at direct risk of being impacted by wildfires. In 1940, the number of wildfire-vulnerable homes was roughly 607,000. In 2010, it was 6.7 million.

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Hurricane Irma: Florida’s Overdevelopment Has Created a Ticking Time Bomb

Scientific American  online


Millions are without power in Florida after Irma—one of the most powerful Atlantic hurricanes on record—swept through the state this weekend before weakening to a tropical storm. It caused its fair share of damage, but Florida’s most ominous fears did not play out; extremely vulnerable eastern coastal areas, including Miami, were spared the worst.

But meteorologist and disaster risk expert Stephen Strader says the state is still in a very dangerous position, due to intense population growth and overdevelopment of its low-lying coastal zones. He predicts it is only a matter of time before another storm devastates the Sunshine State and some of its major cities. And he adds that it is not the only state facing this threat: Overdevelopment and expanding populations across the U.S. mean natural disasters now pose a greater risk to many other places, such as Houston and Oklahoma City.

Scientific American spoke with Strader, an assistant professor of geography and the environment at Villanova University, about why Florida and many other places now face a graver risk from natural disasters—and what officials, developers and the public can do to address the problem.

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Florida hurricanes present and past, and 'disaster amnesia'

The Philadelphia Inquirer  online


The winds that roared through downtown Miami at 115 mph at 5 a.m. died suddenly shortly after 6.

“The streets of the city became crowded with people,” Richard Gray, the U.S. Weather Bureau meteorologist on duty the morning of Sept. 18, 1926, wrote in his compelling account of the storm.

For many of them, the lull was a death trap. It lasted 35 minutes as the eye of the Great Miami Hurricane passed over the city, and despite Gray’s warning that the storm wasn’t over, they perished in the second wave of the hurricane’s fury.

Florida, says Stephen Strader, geography professor at Villanova University, has suffered from a dangerous case of “disaster amnesia.”

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Tornado deaths and destruction to triple in coming decades, study finds

USA Today  


We're already well on our way: In the past several decades, development in the lower 48 states more than quadrupled, said study lead author Stephen Strader of Villanova University's Department of Geography and the Environment.

"Disasters are socially constructed," he said, and we're "building ourselves into disasters"...

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A New Study Explores The Complexities Of Tornadoes, Risk, Poverty, And Housing

Forbes  online


A new study from researchers at Michigan State University examines the growing number of mobile homes in the United States and their inherent vulnerability to tornadic storms. There are roughly 9 million mobile homes in the United States according to a press release sent to me by Andy Henion, Senior Communications Manager at Michigan State University. The United States averages well over 1000 tornadoes per year. The risk of fatalities is greater in mobile homes, which may be the only viable housing option for some people. I wanted to further explore the complexities of risk, poverty, housing, and tornadoes.

The annual impact of tornadoes is expected to increase threefold over the next few decades due to the “twin forces of increased climate variability and growth in the human-built environment”

This was found by Stephen Strader and colleagues in recent paper in the journal Climate Change. Discussions about climate change and tornadoes can be messy, and I have seen very careless discussions on the topic by all sides of the discussion. Dr. Victor Gensini, at the College of Dupage, has lead studies on future climate change and severe weather links. He reminded me that his findings suggest an increase in the mean and variability of future severe weather in vulnerable regions like the Southeast. It is worth noting that a recent National Academies report on attribution of extreme weather and climate concluded that unlike some extreme events (heatwaves, some droughts, extreme precipitation events, etc.) there is lower confidence in attribution of tornadic storms to climate change at this time. This does not mean future studies will not lead to higher confidence, but I urge caution on this particular topic as studies emerge. I agree with the study authors that federal, state, and local policymakers will need to find ways to address such vulnerabilities of residents in mobile homes, particularly if there are future changes in tornado frequency.

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Supermoon comes with supersized tides that could bring coastal flooding

The Christian Science Monitor  online


As the moon passed closer to Earth than at any point since 1948 early Monday morning, it put on a spectacular show, appearing bigger and brighter in the night sky than usual. But while many amateur astronomers looked up at the largest "supermoon" in 68 years travel across the sky last night, officials in coastal areas are keeping a wary watch earthward – specifically, at sea levels.

"This all depends on location," Stephen Strader, geography and environmental science professor at Villanova University near Philadelphia, tells the Monitor in an email. "For instance, locations that are closer to sea-level and near the ocean will be subject to significant flooding with the high tides. Places like Miami, Ft. Lauderdale, Jacksonville, etc. have witnessed fairly significant flooding caused by high tides and the supermoon’s gravitational pull."

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Research Grants (2)

Tornadoes and Mobile Homes: An Inter-science Approach to Reducing Vulnerabilities and Improving Capacities for the Southeast’s Most Susceptible Population

National Oceanic and Atmospheric Administration 

July 2017, The Verification of the Origins of Rotation Experiment in the Southeast U.S. (VORTEX-SE)
Strader, S. M. (Principal), Ashley, W. S. (Co-Principal), Klockow, K. (Co-Prinipal)

Vital Minigrant

Villanova University 

April 2017, Development of Field Exercises and Student Engagement for a New Geography Course on Weather Systems

Select Academic Articles (5)

Projected 21st century changes in tornado exposure, risk, and disaster potential Climate Change


While risk and associated hazard characteristics are important components of disaster formation, the consequences of hazards are often driven by underlying human and built-environment vulnerabilities. Yet, there has been little research conducted on how the evolving contributors of risk and vulnerability commingle to produce disaster potential. In this study, we assess the interaction of risk and vulnerability by investigating a single hazard, the tornado. How future changes in risk and vulnerability influence tornado disaster probability is estimated by integrating, for the first time, projected residential built environment data and modeled future severe weather environments. Results suggest that, although the projected twenty-first century escalation in tornado risk will play a role in increasing disaster consequences and frequency, growth in the human-built environment is projected to outweigh the effects of increased risk on future tornado disaster potential. While changes in societal exposure are projected to overshadow potential climate change-driven alterations in tornado risk, the combination of both an increase in risk and exposure may lead to a threefold increase in median annual tornado impact magnitude and disaster potential from 2010 to 2100.

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Observed and projected changes in united states tornado exposure Weather, Climate, and Society


This study examines how tornado risk and societal exposure interact to create tornado disaster potential in the United States. Finescale historical and projected demographic data are used in a set of region-specific Monte Carlo tornado simulations to reveal how societal development has shaped, and will continue to shape, tornado disaster frequency and consequences. Results illustrate that although the U.S. Midwest contains the greatest built-environment exposure and the central plains experience the most significant tornadoes, the midsouth contains the greatest tornado disaster potential. This finding is attributed to the relatively elevated tornado risk and accelerated growth in developed land area that characterizes the midsouth region. Disaster potential is projected to amplify in the United States due to increasing built-environment development and its spatial footprint in at-risk regions. In the four regions examined, both average annual tornado impacts and associated impact variability are projected to be as much as 6 to 36 times greater in 2100 than 1940. Extreme annual tornado impacts for all at-risk regions are also projected to nearly double during the twenty-first century, signifying the potential for greater tornado disaster potential in the future. The key lesson is that it is the juxtaposition of both risk and societal exposure that drive disaster potential. Mitigation efforts should evaluate changes in tornado hazard risk and societal exposure in light of land-use planning, building codes, and warning dissemination strategies in order to reduce the effects of tornadoes and other environmental hazards.

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A Monte Carlo model for estimating tornado impacts Meteorological Applications

Strader, S. M., T. Pingel, and W. Ashley

2016: 23(2), 269-289
Determining the likelihood and severity of tornado disasters requires an understanding of the dynamic relationship between tornado risk and vulnerability. As population increases in the future, it is likely that tornado disaster frequency and magnitude will amplify. This study presents the Tornado Impact Monte Carlo (TorMC) model, which simulates tornado events atop a user-defined spatial domain to estimate the possible impact on people, the built-environment or other potentially vulnerable assets. Using a Monte Carlo approach, the model employs a variety of sampling techniques on observed tornado data to provide greater insight into the tornado disaster potential for a location. Simulations based on 10 000 years of significant tornado events for the relatively high-risk states of Alabama, Illinois and Oklahoma are conducted to demonstrate the model processes, and its reliability and applicability. These simulations are combined with a fine-scale (100 m), residential built-environment cost surface to illustrate the probability of housing unit impact thresholds for a contemporary year. Sample results demonstrate the ability of the model to depict successfully tornado risk, residential built-environment exposure and the probability of disaster. Additional outcomes emphasize the importance of developing versatile tools that capture better the tornado risk and vulnerability attributes in order to provide precise estimates of disaster potential. Such tools can provide emergency managers, planners, insurers and decision makers a means to advance mitigation, resilience and sustainability strategies.

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Recipe for disaster: How the dynamic ingredients of risk and exposure are changing the tornado disaster landscape Bulletin of the American Meteorological Society


Tornado disasters and their potential are a product of both hazard risk and underlying physical and social vulnerabilities. This investigation appraises exposure, which is an important component and driver of vulnerability, and its interrelationship with tornado risk in the United States since the mid-twentieth century. The research demonstrates how each of these dynamic variables have evolved individually and interacted collectively to produce differences in hazard impact and disaster potential at the national, regional, and local scales. Results reveal that escalating tornado impacts are driven fundamentally by growing built-environment exposure. The increasing tornado disaster probability is not uniform across the landscape, with the mid-South region containing the greatest threat based on the juxtaposition of an immense tornado footprint risk and elevated exposure/development rates, which manifests—at least for one important impact marker—in the area’s high mortality rate. Contemporary, high-impact tornado events are utilized to emphasize how national- and regional-level changes in exposure are also apparent at the scale of the tornado. The study reveals that the disaster ingredients of risk and exposure do vary markedly across scales, and where they have increasing and greater overlap, the probability of disaster surges. These findings have broad implications for all weather and climate hazards, with both short- and long-term mitigation strategies required to reduce future impacts and to build resilience in the face of continued and amplifying development in hazard-prone regions.

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The expanding bull’s eye effect Weatherwise

Strader, S. M., T. Pingel, and W. Ashley

September-October 2015
Weather hazards such as tornadoes and hurricanes affect thousands of people annually, often resulting in casualties and billions of dollars in damage. These extreme weather events can lead to disasters, which are a product of both hazard risk and societal exposure. Hazard risk describes the frequency and magnitude of a weather hazard, while societal exposure is defined as who and what is affected by an event. The NOAA reports that there have been nearly 180 weather and climate disasters in the United States since 1980 that have cost a $1 billion or more, with the total cost of these events exceeding $1 trillion! The number of billion dollar events has been increasing over time, begging the question: Is this trend due to more extreme events, or are changes in society to blame for the alarming increase? In this article, we will assess the latter factor by exploring population increase, intensifying development, and the extensive history of rural-to-urban migration, placing these demographic shifts in the context of increasing disasters in the United States. Since 1940, developed land represented only 2.5% of the total land area in the United States, but, by the end of the 21st century, urban and suburban development could make up as much as 18% of the conterminous land area. Could future growth in the number of people and their assets exposed to these hazards lead to increased disaster frequency and magnitude? How many people could potentially be affected if a violent tornado struck Atlanta, Georgia; Chicago, Illinois; or Dallas, Texas, in the future? What if a potentially catastrophic hurricane made a direct hit on Houston, Texas; Miami, Florida; or New York, New York?

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