Hurricanes, Typhoons and Cyclones

A tropical cyclone “is a rotating, organized system of clouds and thunderstorms that originates over tropical or subtropical waters and has a closed low-level circulation.”

Hurricanes, typhoons and cyclones are different names for the same hazard, which meteorologists worldwide officially recognize as “tropical cyclones.” These storm systems are called “cyclones” in the South Pacific and Indian Ocean, “typhoons” in the western North Pacific Ocean, and “hurricanes” in the Central and Eastern North Pacific as well as the Atlantic Ocean.

The Saffir-Simpson Hurricane Wind Scale measures the intensity of hurricanes using a one-to-five rating based on the storm’s maximum sustained wind speed. This video from NOAA shows how increasing winds cause more sustained damage. However, this scale does not consider the amount of rain or storm surge, which can significantly impact the damage level, even far inland. For example, the most significant impacts from Hurricane Helene in 2024 occurred 800 miles inland, including wind damage and extensive flooding.

The seven main cyclone regions are located near warm ocean waters of at least 80°F. Cyclones usually form at least 300 miles or between 5° and 30° latitudes, either north or south of the equator. In May 2024, Cyclone IALY became the “most northerly tropical cyclone, forming at 4.7°S” and dissipating at 1.4°S.

Each cyclone region has a specific season, and at least one area is “in season” every month of the year.

Due to climate change, ocean temperatures are increasing, which helps trigger the development of tropical cyclones. These warmer waters will cause storms to track to unusual places, and new communities across the globe will need to prepare for the associated risks.

The world is urbanizing, and coastal cities are facing increasing levels of vulnerability to tropical cyclones due to sea-level rise, the loss and destruction of natural coastal defenses (such as mangrove forests), and increased storm intensity.

Vulnerability in coastal communities worldwide is compounded by socio-economic inequalities, urban development, inadequate infrastructure, lack of preparedness and poor communication. These all intensify the impacts of disasters, leading to significant economic losses and human displacement.

Tropical storms have changed due to climate change, resulting in new storm patterns that reach previously unexposed populations. As communities are exposed to risks and hazards that are outside their previous experiences, they often lack the knowledge on how to respond.

Funders can play a critical role in reducing cyclone impacts. Investments should span preparedness, mitigation, response and long-term recovery. Rebuilding efforts must include FORTIFIED housing, “a collection of construction upgrades that work together to protect your home from severe weather.”

Early warning systems and preparedness interventions must reach people who have never experienced a tropical cyclone.

Building up natural and man-made protections, like Bangladesh’s mangroves or Vietnam’s dikes, is vital as they can help prevent storm surge from impacting communities.

Messaging must be precise, prescriptive, readily available and accessible. It should be inclusive for people with disabilities, for example, press conferences providing warnings about a pending cyclone should include ASL translation, and be available in multiple languages.

It is essential to support local organizations in advance to ensure they have the necessary supplies and resources to respond when a storm hits, as external organizations may not be able to enter the affected area immediately. Mutual aid organizations are one option funders can support, as they reach marginalized communities.

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(Photo: Destruction can be seen from the air in and around Marathon, Florida as recovery efforts continue following Hurricane Irma. Credit: U.S. Customs and Border Protection photo by Kris Grogan)