Areas of Expertise (4)
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.
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)
- American Meteorological Society
- Association of American Geographers
- Sigma Xi Scientific Research Society
- Gamma Theta Upsilon Geography Honor Society
Select Media Appearances (5)
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.
You research risk and disaster potential in storm-vulnerable areas. What have you discovered about places like Florida?
A few years ago, Walker Ashley at Northern Illinois University and I started developing this idea called the expanding bull’s-eye effect. It basically says that as cities grow and there are more people, we’re seeing increased disaster potential—more and more people are being affected by disasters.
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.
They had spent the night in downtown buildings and they “rushed out to view the wreckage that filled the streets.”
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.
A lot has changed since then. The Sunshine State’s population grew from 1.5 million in 1930 to 20.6 million today. Statewide, the value of insured property in Florida coastal areas is about $2.9 trillion, according to the Insurance Information Institute.
Florida, says Stephen Strader, geography professor at Villanova University, has suffered from a dangerous case of “disaster amnesia.”
Tornado deaths and destruction to triple in coming decades, study finds
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"...
A New Study Explores The Complexities Of Tornadoes, Risk, Poverty, And Housing
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.
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."
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)
April 2017, Development of Field Exercises and Student Engagement for a New Geography Course on Weather Systems
Select Academic Articles (5)
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.
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.
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.
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.
Strader, S. M., T. Pingel, and W. Ashley
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?