Categorizing Chaos

Tropical cyclones are powerful, rotating storm systems that form over warm ocean waters near the equator. These storms are fueled by heat and moisture from the sea and are known for their intense winds, heavy rains, and spiral structure (NOAA 2023).

These powerful storm systems often include multiple hazards such as extreme winds, heavy rainfall, storm surges and flooding, lightning, and tornadoes.

The combination of these hazards makes tropical cyclones one of the most significant threats to human life and property.

Hurricanes, Typhoons, and Cyclones are different names describing the same type of weather phenomenon known scientifically as Tropical Cyclones.

The term used depends on its geographic location.

Storms occurring in the Caribbean Sea, the Gulf of Mexico, the North Atlantic Ocean, and the eastern and central North Pacific Ocean are called  hurricanes .

Locations on the map: 1  and  2

These weather phenomena are known as  typhoons  in the western North Pacific Ocean.

Locations on the map: 3

These meteorological events are commonly designated as  cyclones  in the regions of the Bay of Bengal, Arabian Sea, western South Pacific, and Indian Ocean.

Locations on the map: 4  and  5

Source:      World Meteorological Organization (WMO) 

Tropical cyclones derive their energy from heat and moisture and typically form in regions near the equator, where ocean surface temperatures reach at least 80°F (27°C) (NOAA 2023).

The process begins when warm, moist air from the ocean surface evaporates. As this warm air rises, it creates a low-pressure area beneath it. The rising air cools, causing water vapor to condense into clouds, which releases heat that further energizes the upward movement of air (American Meteorological Society 2022). This system intensifies as more warm, moist air rushes in to replace the rising air. As the cycle continues, a spiraling pattern emerges due to the Earth’s rotation, known as the Coriolis effect. This rotation forms a large cloud structure characterized by a distinct calm center, referred to as the eye.

Conditions within the eye are remarkably calm compared to the surrounding storm. The strongest section of a tropical cyclone is known as the eye wall, which contains the highest winds and heaviest rainfall (Smith 2021). Extending outward from the eye wall are spiraling bands of clouds and rain, known as rain bands, which bring heavy rainfall and flooding far from the storm's center.

Tropical cyclones need a steady supply of moisture and heat to grow stronger; as long as these warm, moist conditions continue, the storm can intensify (American Meteorological Society 2022). However, as it moves over land or cooler waters, the tropical cyclone loses its energy source and gradually weakens.

Tropical cyclones above a particular sustained wind speed are further classified into categories for tracking and public safety purposes.

To classify tropical cyclones, meteorologists use the Saffir-Simpson Hurricane Wind Scale, which is a five-level system used to categorize hurricanes based on their sustained wind speeds, with Category 5 being the most intense (NOAA 2023).

This scale enables governments and people to better understand the storm’s potential impact on buildings, infrastructure, and communities. Understanding the nature of tropical cyclones and being prepared is crucial for those living in areas prone to these powerful storms.

Wind Speeds 74-95 mph (119-153 km/h) – Minimal Damage

Category 1 tropical cyclones have sustained winds between 74 and 95 mph, which can cause relatively minor structural damage. Although not the most destructive on the scale, Category 1 tropical cyclones are still dangerous, with winds powerful enough to snap tree branches, uproot smaller trees, and damage roof shingles, gutters, and siding on homes. Power outages are common in Category 1 storms due to fallen branches hitting power lines, but these are usually localized. Coastal flooding may occur in low-lying areas, and piers and other waterfront structures may experience some damage from rising water levels. Although the impact is less severe than in higher categories, a Category 1 weather event still requires preparation, as even minimal flooding and wind can make roadways hazardous and create dangerous debris (National Hurricane Center 2023).

Tropical Cyclone Oscar developed over the warm waters of the North Atlantic off the west coast of Africa, slowly gaining strength until it reached Category 1 status, with winds peaking at 85 mph (140 km/h). Although Oscar was not among the most powerful storms of the season, its expansive wind field posed a significant threat to Bermuda’s coastal regions, where rough seas and high winds created dangerous conditions for small vessels and vulnerable structures along the shore (National Hurricane Center 2024). As Oscar drew closer, Bermuda’s local officials issued advisories urging residents to secure their homes and avoid coastal areas. The island’s emergency management team activated plans to open shelters and notified the community, especially boaters, of the approaching storm.

Thanks to prompt and clear communication, the response to Oscar was swift. Many residents followed the advisories by reinforcing windows, securing loose outdoor items, and preparing emergency supplies in case of power outages. Small craft warnings were especially effective, as boat owners secured or moved vessels to safe harbor, reducing the potential for damage and accidents (Smith 2024). However, some areas in Bermuda’s more remote regions experienced delays in receiving updates and advisories, which led to confusion and left certain residents with minimal time to prepare. Additionally, several older neighborhoods experienced brief but recurring power outages as winds knocked down branches onto power lines, illustrating the challenge of infrastructure resilience against even moderate storms.

Geospatial technology, particularly satellite tracking, played a pivotal role in predicting Oscar’s path and assessing which areas of Bermuda would be most affected. These tools allowed emergency managers to focus resources where they were needed most, but public access to real-time mapping data could have made the response even more efficient. If residents, particularly in remote areas, had access to live updates on the storm’s path and potential impacts through mobile apps or interactive maps, they could have better anticipated the storm’s arrival, improving safety and reducing last-minute preparation issues. Bermuda’s emergency planners are now exploring ways to expand community access to geospatial data, recognizing that better public integration of these technologies could strengthen responses to future storms (Brown et al. 2024).

Wind Speeds 96-110 mph (154-177 km/h) – Moderate Damage

Category 2 tropical cyclones bring sustained winds of 96 to 110 mph, causing moderate damage to buildings and infrastructure. Roofs, siding, and windows on homes and other buildings can be heavily impacted, with the potential for more extensive roof damage compared to Category 1 storms. Larger trees are likely to be uprooted, and more substantial power outages are expected, often lasting days due to the volume of downed trees and damaged power lines. Mobile homes and less stable structures are at a higher risk of significant damage or destruction. Coastal flooding risks increase, and storm surges can cause damage to piers and other structures along the waterfront. Evacuations may be recommended for vulnerable areas as the strength and associated flooding can create life-threatening situations (Smith 2021).

Wind Speeds 111-129 mph (178-208 km/h) – Extensive Damage (Major Hurricane)

Category 3 tropical cyclones mark the point at which storms are considered “major hurricanes” due to their life-threatening intensity and potential for extensive damage. With sustained winds between 111 and 129 mph, these storms can cause severe damage to homes, particularly roofs and exterior walls, and often result in widespread power outages that can last for days to weeks. Larger trees and power poles are frequently downed, making many roads impassable and delaying emergency and utility services. Coastal flooding becomes a serious threat, with storm surges capable of submerging low-lying areas, eroding coastlines, and destroying piers. The intensity of a Category 3 storm requires extensive preparations, often leading to mandatory evacuations in affected areas (American Meteorological Society 2022).

Tropical Cyclone John barreled through the Eastern Pacific during the summer of 2024, reaching Category 3 strength as it approached the Baja California peninsula. With sustained winds of 120 mph (195 km/h) and intense rainfall, John posed a serious threat to the coastal areas of Mexico, which braced for the storm’s potential to cause widespread damage (National Hurricane Center 2024). As John inched closer, local authorities moved quickly, issuing evacuation orders for at-risk coastal communities and preparing shelters further inland. Emergency teams coordinated transportation for those without access to vehicles, ensuring that residents could reach safer areas.

Early warnings and organized evacuations saved lives, as most residents heeded instructions and moved to emergency shelters, which were stocked with food, water, and medical supplies. The rapid response from emergency services also allowed for efficient resource distribution, minimizing the impact on human life (Garcia 2024). Some residents were hesitant to evacuate, either because of concerns about leaving property behind or because of uncertainty about the storm’s final trajectory. This last-minute hesitation led to road congestion, making it challenging for emergency vehicles to navigate evacuation routes and causing delays in reaching certain areas.

Digital mapping and geospatial tools played a vital role in tracking Hurricane John’s path and pinpointing high-risk zones. This technology allowed authorities to design effective evacuation routes and set up shelters strategically. However, greater public access to real-time mapping and route updates could have eased traffic congestion by helping residents avoid clogged roads and identify alternative routes. The use of drones for post-storm assessments would have also been beneficial, providing real-time visuals of blocked roads and damaged areas to aid recovery efforts. Officials are now considering investments in geospatial technology to improve future response times and support emergency management during similar events (Smith 2024).

Wind Speeds 130-156 mph (209-251 km/h) – Severe Damage (Major Hurricane)

Category 4 tropical cyclones are extremely dangerous, with sustained winds between 130 and 156 mph. These storms can cause catastrophic damage, severely impacting well-built homes by ripping off roofs and some exterior walls. Nearly all trees, power poles, and street signs are expected to be downed, isolating neighborhoods and making large areas inaccessible. Water and power outages are extensive and can last for weeks in the hardest-hit locations. Coastal areas face serious storm surge threats, often with flooding that reaches several miles inland, submerging buildings and cutting off evacuation routes. Category 4 weather events can render areas uninhabitable for long periods, and residents in affected areas are typically required to evacuate (National Hurricane Center 2023).

Tropical Cyclone Helene swept into Florida’s Big Bend region with unexpected ferocity, intensifying rapidly just before landfall and catching many residents off guard. By the time Helene struck the coast, it had reached Category 4 strength, with sustained winds of 140 mph (220 km/h) and relentless rain that led to a massive storm surge, flooding homes and submerging roads throughout the region (NOAA 2024). The storm’s impact on the low-lying coastal communities was severe, as homes, infrastructure, and natural areas all suffered under Helene’s force. Local emergency teams, well aware of the dangers posed by Helene’s rapidly evolving path, quickly issued evacuation orders and set up shelters in safer inland areas, where residents could find refuge from the storm’s onslaught.

Thanks to prompt communication, most residents heeded the warnings and evacuated, filling shelters that had been well-stocked with supplies in advance, minimizing injuries and fatalities (Smith 2024). For some, however, the storm’s rapid intensification created hesitation, with concerns over property security leading to last-minute departures. This resulted in traffic congestion along main routes, which complicated the evacuation process. Additionally, the storm exposed weaknesses in older drainage systems, which were unable to handle the heavy rains, leading to extended flooding in many neighborhoods.

Despite these challenges, geospatial technology proved essential for tracking Helene’s path and identifying potential flood zones, allowing emergency teams to prioritize high-risk areas. Satellite imagery and flood maps helped responders anticipate damage, though access to real-time drone imagery could have enhanced this assessment, especially after the storm, providing faster updates on road blockages and identifying isolated residents who needed immediate help. Expanding the use of drones in hurricane response could provide a valuable tool in the future, allowing teams to allocate resources more efficiently and protect vulnerable communities from the impacts of increasingly intense storms (Brown et al. 2024).

Wind Speeds 157 mph or higher (252 km/h or higher) – Catastrophic Damage (Major Hurricane)

Category 5 tropical cyclones are the most severe, with sustained winds exceeding 157 mph. These storms bring near-total destruction to buildings and infrastructure, often leveling entire neighborhoods. Well-built homes and commercial buildings can experience complete roof and wall collapse, leaving many areas uninhabitable for weeks or even months. Virtually all trees, power poles, and streetlights are downed, while critical infrastructure like water and sewage systems can be destroyed, requiring long-term repair or reconstruction. Storm surges in Category 5 tropical cyclones reach extreme heights, potentially flooding entire coastal regions and displacing thousands of people. Category 5 storms demand the most intense preparations and evacuation measures, as their scale of destruction and disruption is life-threatening and widespread (Ahrens 2020).

Tropical Cyclone Milton struck the Gulf Coast of the United States with unprecedented strength, becoming one of the most powerful hurricanes in recent history. Reaching Category 5 status, Milton packed sustained winds exceeding 160 mph (257 km/h), leveling entire neighborhoods and leaving a path of destruction across coastal communities (NOAA 2024). Milton’s rapid intensification over warm Gulf waters gave residents and officials only a brief window to prepare for landfall. When it came ashore, the storm unleashed massive storm surges that flooded low-lying areas and caused severe damage to infrastructure, uprooting trees, snapping power poles, and toppling buildings. The human response was a race against time; authorities issued mandatory evacuation orders well in advance, moving thousands of residents out of high-risk areas and setting up emergency shelters inland.

Thanks to early warnings and robust pre-planning, many lives were saved, as the majority of residents complied with evacuation orders, filling shelters stocked with essential supplies and medical resources (Smith 2024). Despite these efforts, Milton’s sheer power overwhelmed the power grid and emergency infrastructure, leading to prolonged outages that left some areas without power or water for weeks. Roadways and bridges suffered extensive damage, making it challenging for emergency teams to reach affected areas quickly.

Geospatial technology, including satellite tracking and predictive modeling, played a crucial role in forecasting Milton’s path, allowing emergency services to allocate resources and direct evacuations. Real-time drone imagery and flood mapping, however, could have further enhanced response efforts by providing up-to-date information on inaccessible areas and flood conditions, helping to prioritize urgent needs and streamline resource distribution. In the wake of Milton, officials are now looking to expand drone use and enhance geospatial infrastructure to ensure more efficient and responsive emergency services in the face of future high-intensity storms (Brown et al. 2024).

Each category on the Saffir-Simpson scale gives communities a clear understanding of the potential impact and helps officials implement appropriate safety and evacuation measures based on the storm’s expected intensity.

Use the buttons below to explore the map and uncover detailed information about historical tropical cyclones.

Each button filters the map to display tropical cyclones by their specific Saffir-Simpson scale category. Simply click a button to focus on the data you’re most interested in.

American Meteorological Society (AMS). 2022. AMS Glossary of Meteorology. https://glossary.ametsoc.org.

Brown, Lisa, et al. 2024. “Enhancing Public Access to Geospatial Data During Hurricanes: Insights from Hurricane Oscar.” Journal of Disaster Management.

Brown, Lisa, et al. 2024. “Expanding Geospatial Technology for Hurricane Response: Lessons from Hurricane Milton.” Journal of Emergency Management.

Brown, Lisa, et al. 2024. “Improving Flood Response with Geospatial Technology: Lessons from Cyclone Helene.” Journal of Disaster Management.

Brown, Lisa, et al. 2024. “Improving Public Access to Geospatial Data During Storm Events: Case Studies from Hurricane Oscar.” Journal of Disaster Preparedness.

Garcia, Juan. 2024. Digital Mapping and Evacuation Planning: A Case Study on Hurricane John. Journal of Emergency Response Planning.

National Hurricane Center. 2024. Atlantic Hurricane Report: Hurricane Oscar. https://www.nhc.noaa.gov.

National Hurricane Center. 2024. Atlantic Tropical Cyclone Report: Hurricane Oscar. https://www.nhc.noaa.gov.

National Hurricane Center. 2024. Eastern Pacific Tropical Cyclone Report: Hurricane John. https://www.nhc.noaa.gov.

National Oceanic and Atmospheric Administration (NOAA). 2023. “Hurricanes: Science and Society.” https://www.noaa.gov/hurricanes.

National Oceanic and Atmospheric Administration (NOAA). 2024. “Big Bend Hurricane Developments: Hurricane Helene.” https://www.noaa.gov.

National Oceanic and Atmospheric Administration (NOAA). 2024. “Gulf Coast Hurricane Impacts: Hurricane Milton.” https://www.noaa.gov.

National Oceanic and Atmospheric Administration (NOAA). 2024. “North Atlantic Cyclone Developments: Hurricane Oscar.” https://www.noaa.gov.

Smith, James. 2021. Understanding Weather and Climate Patterns. New York: McGraw-Hill Education.

Smith, James, and Emily Jones. 2022. Geospatial Technology in Marine and Coastal Emergency Response. Boston: McGraw-Hill.

Smith, Robert. 2024. “Community Preparedness and Infrastructure Resilience in Hurricane-Prone Areas: The Case of Hurricane Helene.” Journal of Coastal Infrastructure and Safety.

Smith, Robert. 2024. “Evaluating Bermuda’s Emergency Response Infrastructure: A Case Study of Hurricane Oscar.” North American Journal of Emergency Preparedness.

Smith, Robert. 2024. “Evaluating Infrastructure Resilience in the Face of Moderate Hurricanes: Lessons from Hurricane Oscar.” North American Journal of Infrastructure and Community Safety.

Smith, Robert. 2024. “Improving Traffic Flow and Community Safety During Hurricanes: Lessons from Hurricane John.” North American Journal of Infrastructure Resilience.

Smith, Robert. 2024. “Power Grid Resilience and Emergency Response in High-Intensity Hurricanes: The Case of Hurricane Milton.” North American Journal of Infrastructure Resilience.

Smith, Robert. 2024. “Resilient Infrastructure Planning for High-Intensity Cyclones: The Case of Cyclone Milton.” North American Journal of Infrastructure Resilience.