Downtown Houston, Texas (4kclips/Shutterstock)
In a nutshell
- A May 2024 derecho shattered thousands of windows in Houston’s high-rises, while Hurricane Beryl caused far less damage, despite comparable wind speeds, revealing that not all wind events are equally destructive.
- Wind tunnel tests showed that downburst winds, typical of derechos, create much stronger suction forces on building sides, up to 33% higher than hurricane winds of the same speed, posing unique risks for urban skyscrapers.
- Current building codes focus on hurricanes but may ignore the real dangers of thunderstorm winds in dense cities. Researchers argue it’s time to adapt standards to better reflect how wind interacts with tall buildings in crowded urban environments.
MIAMI — Houston, we have a problem. In 2024, downtown Houston became an unintended laboratory for studying extreme weather impacts when two powerful storms hit the city just months apart. First came a violent derecho in May, and then Hurricane Beryl followed in July. Though both storms packed winds of similar strength, they left dramatically different damage patterns across Houston’s skyline.
Houston’s downtown buildings were supposedly designed to handle winds up to 150 mph. Yet the derecho, with winds reaching only about 100 mph, shattered around 3,250 windows across 18 skyscrapers. When Hurricane Beryl blew through with comparable 83-90 mph winds two months later, the damage was surprisingly mild with just 40 buildings reporting minor issues.
The Damage Mystery
This strange contrast caught the attention of researchers at Florida International University, who wanted to know why similar wind speeds from different types of storms could cause such wildly different outcomes. Their findings, published in Frontiers in Built Environment, indicate we might need to rethink building design standards, especially for non-hurricane wind events.
The research team examined several prominent Houston skyscrapers after both storms, including the Chevron Building Auditorium, CenterPoint Energy Plaza, and El Paso Energy Building. They discovered that damage wasn’t random but followed specific patterns revealing weakness points in tall building design.
Take the Chevron Building Auditorium, for example. During the derecho, numerous glass panels broke loose from its façade, creating hazardous conditions as debris rained down on streets below. The damage concentrated on curved surfaces and sides facing other tall buildings. This pattern repeated across other structures, with corners and sides facing neighboring buildings taking the worst hits.
Different Winds, Different Pressures
To figure out what was happening, the research team turned to wind tunnel testing. At Florida International University’s Wall of Wind facility, they built scale models of tall buildings and tested them under two different wind conditions: traditional hurricane-like winds and downburst winds typical of derechos and thunderstorms.
While hurricanes create a wind profile that gradually increases with height, downbursts produce a “nose-shaped” profile where maximum winds hit closer to the ground. This fundamental difference creates entirely different pressure patterns on building surfaces.
The team found that downburst winds generate much stronger suction forces on building sides compared to hurricane winds of identical speeds. In some tests, these suction forces were up to 33% higher during simulated downburst conditions. This helps explain why façades were more likely to fail during the derecho than during Hurricane Beryl.
The research also revealed that the “urban canyon” effect, where wind gets channeled between closely spaced buildings, becomes more intense during downburst conditions. When buildings stood close together in their tests, the normally positive pressure on windward walls transformed into strong negative pressure (suction), potentially contributing to glass failures.
“When strong winds move through a city, they can bounce due to interference between tall buildings. This increases pressure on walls and windows, making damage more severe than if the buildings were isolated,” says study author Omar Metwally from Florida International University, in a statement.
Building Better for All Wind Types
Current building codes focus primarily on hurricane resistance but may overlook the unique loading patterns created by derechos and downbursts. As climate change potentially increases severe weather frequency, this knowledge gap becomes increasingly problematic.
The study also emphasizes the importance of urban context when designing tall buildings. A skyscraper that works perfectly as a standalone structure might face much higher wind loads when surrounded by neighboring towers, calling for more site-specific approaches to wind engineering.
Building owners and city planners need a broader perspective on wind hazards beyond just hurricane preparedness. The Houston case study offers rare documentation of real-world storm effects, giving researchers invaluable data to improve building resilience. By connecting actual damage patterns with wind tunnel findings, this work helps bridge the gap between theory and practice in wind engineering.
As urban development pushes skyward, this research reminds us that despite technological advances, we remain subject to nature’s forces. Building resilience demands not just stronger materials but deeper knowledge of how wind behaves in complex urban environments.
Paper Summary
Methodology
The researchers documented building damage after both storms through site visits and photographs, mapping damage locations relative to wind direction and surrounding buildings. They then conducted wind tunnel testing at Florida International University using a 1:350 scale model of a typical tall building equipped with 300 pressure sensors. The model was tested under both atmospheric boundary layer (hurricane-like) winds and downburst (derecho-like) conditions. To study building interference effects, they positioned a second identical model at various distances upstream and measured resulting pressure changes.
Results
The study found significant differences between downburst and hurricane wind effects. Downburst winds created 33% stronger suction forces on building sides (negative pressure coefficients of -1.6 versus -1.2 for hurricane winds). Building spacing dramatically affected pressures—when buildings stood just one building-width apart, the windward wall experienced suction rather than positive pressure. These interference effects diminished with increased distance but normalized more slowly in downburst conditions. Downbursts also created more fluctuating pressures on the lower part of windward walls but generally less turbulence elsewhere compared to hurricane winds.
Limitations
The study used a generic tall building model rather than replicas of specific Houston buildings, limiting direct comparison. The simulated downburst used a simplified 2-D wall jet approach that may not capture all aspects of real-world downbursts. The research focused primarily on pressure measurements rather than structural or façade system responses. Limited information about the specific façade designs of damaged Houston buildings made it difficult to determine exact failure mechanisms. Interference testing only examined buildings directly upstream of the test model, not the full range of arrangements found in dense urban environments.
Discussion and Takeaways
Current building codes may inadequately address non-hurricane wind events like derechos and downbursts, which can create significantly higher suction forces on building sides and corners. Urban context substantially influences wind loads, with neighboring buildings potentially doubling negative pressures on façades. This necessitates site-specific wind assessments rather than treating buildings as isolated structures. Building maintenance should prioritize corners, curved surfaces, and sides facing other tall buildings, as these areas proved most vulnerable during extreme wind events.
Funding and Disclosures
The research received financial support from the National Science Foundation through multiple grants, including NSF Awards No. 1520853 and No. 2037899 for the wind tunnel facility, and “NSF-CMMI Award #2146277” for the broader research program. The authors declared no conflicts of interest.
Publication Information
This study, “Wind load impact on tall building facades: damage observations during severe wind events and wind tunnel testing,” was published in Frontiers in Built Environment (Volume 10, Article 1514523) on February 21, 2025. The research team included five authors from Florida International University’s Department of Civil and Environmental Engineering and Extreme Events Institute. The paper is freely available online under the Creative Commons Attribution License.
