# Hurricanes and Typhoons - Source: Kiddle (kids.kiddle.co), CC BY-SA 3.0, Kiddle encyclopedia, adapted from Wikipedia - Reading level: Grade 5 - Subjects: Weather, Nature, Science - Topics: tropical, ocean, cyclone, storm, winds, cyclones - Length: 1261 words, about 9 min - Published: 2026-05-05 - Original: - Page: - Open in Sprouts: ![Juan 28 oct 1985 2034Z N9](https://sprout.rootsofreason.org/media/kiddle-hurricanes-and-typhoons-1c898a830c.jpg) Hurricane Juan (1985) ![Rita-satellite loop](https://sprout.rootsofreason.org/media/kiddle-hurricanes-and-typhoons-1051bb8695.gif) Hurricane Rita 24 hours after its peak intensity A **tropical cyclone** is a huge spinning storm that forms over warm ocean waters near the Earth's Equator. These powerful storms bring very fast winds and heavy rains. Some tropical cyclones stay over the sea, but others move onto land. They can be very dangerous because they cause floods and their strong winds can pick up and throw objects, even large ones like small boats, at high speeds. Tropical cyclones, also known as hurricanes or typhoons, start when warm, moist air above the ocean rises. This happens when the ocean water is about 80 °F (27 °C) or warmer. As the air rises, the Earth's spin (called the Coriolis effect) makes the winds start to rotate. These storms usually travel west in tropical areas, and then might turn north or south into cooler regions. The calm center of the storm is called the "eye of the storm". It has little rain or wind. Around the eye is the "eyewall," which has the heaviest rain and the fastest winds. Outside the eyewall are rain bands that also have strong winds. Tropical cyclones get their power from warm, humid ocean air. They lose strength when they move over land or cooler ocean water. They die out if they stay over land or cold water for too long. ## How Tropical Cyclones Get Their Names Tropical cyclones are given names to help people track them, predict where they're going, and report on them. A storm gets a name once its winds reach a steady speed of 62 km/h (39 mph). Groups from the World Meteorological Organization choose these names. Once a cyclone is named, it usually keeps that name. For hundreds of years, hurricanes were named after saints. In 1887, an [Australian](https://sprout.rootsofreason.org/r/kiddle/australia) weather expert named Clement Wragge started giving women's names to tropical cyclones. Later, during World War II, storms were named using the phonetic alphabet (like Able, Baker, Charlie). In 1953, the United States began using only female names for these storms. This changed in 1978 when both male and female names were used for storms in the Pacific. By 1979, this practice was also used for hurricanes in the Gulf of Mexico and the Atlantic Ocean. ## Types of Tropical Cyclones Tropical cyclones are put into different groups based on how strong they are and where they form. The National Hurricane Center, which watches storms in the Atlantic and parts of the Pacific Ocean, uses the Saffir-Simpson Hurricane Scale to classify them. Storms in other places, like the Western Pacific Ocean or the Southern Hemisphere, use similar scales. For example, a tropical storm in the western Pacific that reaches hurricane-strength winds is officially called a *typhoon*. ### Tropical Depression A **tropical depression** is an organized group of clouds and [thunderstorms](https://sprout.rootsofreason.org/r/kiddle/thunderstorms) with a clear spinning motion near the ocean surface. Its strongest steady winds are less than 62 km/h (38 mph). It doesn't have an eye and usually doesn't look like the spiral shape of stronger storms. Only the Philippines usually name tropical depressions. ### Tropical Storm A **tropical storm** is an organized system of strong thunderstorms with a very clear spinning motion at the surface. Its steady winds are between 62 and 117 km/h (39–73 mph). At this stage, the storm starts to look like a cyclone, but it usually doesn't have a clear eye. Most weather agencies start naming storms when they reach this strength. ### Hurricane, Typhoon, or Cyclone A **hurricane**, **typhoon**, or **cyclone** is a large spinning [weather](https://sprout.rootsofreason.org/r/kiddle/weather) system with steady winds of at least 118 km/h (74 mph). A tropical cyclone this strong usually develops an eye. The eye is a calm area at the center of the storm. From space, the eye often looks like a small, clear, round spot without clouds. Around the eye is the eyewall, where the strongest thunderstorms and winds spin around the storm's center. The fastest steady winds ever found in tropical cyclones are thought to be around 305 km/h (190 mph). ## Different Names for Tropical Cyclones The term "tropical cyclone" is a general name. In different parts of the world, these storms have other local names: - In the Atlantic Ocean and the eastern, central, and northern Pacific Ocean, a tropical cyclone is called a **hurricane**. - In the western Pacific, it's called a **typhoon**. - In the Indian Ocean, it's simply called a "cyclone". ## How Tropical Cyclones Form ![Hurricane-en](https://sprout.rootsofreason.org/media/kiddle-hurricanes-and-typhoons-cf48e3e1cb.png) Diagram of a tropical cyclone in the Northern Hemisphere Tropical cyclones usually form during the summer, but they can happen in almost any month in most tropical ocean areas. Storms on either side of the Equator often start in the Intertropical Convergence Zone. This is where winds from the northeast and southeast meet. In this wide area of low pressure, air gets heated over the warm tropical ocean and rises in separate pockets, forming thunderstorms. These storms often group together into large clusters. This creates a flow of warm, moist air that rises quickly and starts to spin as it interacts with the Earth's rotation. Several things are needed for these thunderstorms to grow into a tropical cyclone: - Ocean water temperatures must be around 27 °C (80 °F) or warmer. - There needs to be low vertical wind shear around the storm. This means winds at different heights aren't blowing in too many different directions. - The atmosphere needs to be unstable. - There must be high humidity (lots of moisture) in the lower and middle parts of the troposphere. - Enough Coriolis force is needed to help a low-pressure center develop. - There needs to be an existing area of low pressure or a disturbance to start things off. ## When Storms Get Stronger Quickly Sometimes, tropical cyclones can get much stronger very fast. This is called rapid intensification. It means the storm's strongest steady winds increase by 56 km/h (35 mph) or more within 24 hours. For this to happen, the ocean water must be extremely warm (near or above 30 °C or 86 °F). Also, this warm water needs to be deep enough so that waves don't bring cooler water up to the surface. ## How Tropical Cyclones Weaken and Disappear ![Paulette 2020-09-10 1200Z](https://sprout.rootsofreason.org/media/kiddle-hurricanes-and-typhoons-16e108de40.png) Hurricane Paulette, in 2020, is an example of a sheared tropical cyclone, with deep convection slightly removed from the center of the system. A tropical cyclone can weaken or lose its tropical features in several ways. This includes moving over land, going over cooler water, running into dry air, or interacting with other weather systems. However, even after a storm weakens, its leftover parts could sometimes form a new tropical cyclone if conditions become right again. A tropical cyclone can weaken when it moves over waters that are much cooler than 26.5 °C (79.7 °F). This takes away the warm, moist air the storm needs, causing it to lose its warm center and thunderstorms. It then becomes a leftover area of low pressure. These leftover systems can last for several days before completely disappearing. This way of weakening is most common in the eastern North Pacific. If a tropical cyclone moves over land or an island, its spinning motion can start to break down, especially if it hits mountains. When a storm makes landfall on a large landmass, it loses its supply of warm, moist ocean air and starts to pull in dry air from the land. This, along with more friction over land, causes the storm to weaken and disappear. Over mountains, a storm can weaken very quickly. Over flat areas, it might last for two to three days before breaking apart. ## Picture credits - NOAA, Public domain () - NOAA, Public domain () - Kelvinsong, CC BY 3.0 () - NOAA, Public domain ()