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Old Monday, October 25, 2010
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Default What are Tornado, Hurricane, Cyclone and Typhoon ?


A tornado is a violently rotating column of air extending between, and in contact with, a cloud and the surface of the earth.
Tornadoes are generally spawned by thunderstorms, though they have been known to occur without the presence of lightning. The stronger tornadoes attain an awe-inspiring intensity, with wind speeds that exceed 200 mph and in extreme cases may approach 300 mph.
Tornado wind speeds are estimated after the fact based on the damage they produce. Tornadoes are categorized on a scale of 0 (weakest) to 5 (strongest)
The United States has the highest incidence of tornadoes worldwide, with more than 1,000 occurring every year. This is due to the unique geography that brings together polar air from Canada, tropical air from the Gulf of Mexico, and dry air from the Southwest to clash in the middle of the country, producing thunderstorms and the tornadoes they spawn.
Tornadoes can come one at a time, or in clusters, and they can vary greatly in length, width, direction of travel, and speed. They can leave a path 50 yards wide or over a mile wide. They may touch down for only a matter of seconds, or remain in contact with the ground for over an hour.


A hurricane is an intense, rotating oceanic weather system that possesses maximum sustained winds exceeding 119 km/hr (74 mph). It forms and intensifies over tropical oceanic regions.
Hurricanes are generally smaller than storms in mid-latitudes, typically about 500 km (311 miles) in diameter. At the ocean’s surface, the air spirals inward in a counterclockwise direction. This cyclonic circulation becomes weaker with height, eventually turning into clockwise (anticyclonic) outflow near the top of the storm.
Hurricanes form and intensify over oceanic regions. They require sea-surface temperatures of at least 26°C (80°F) and the influence of the earth’s rotation to initiate a spinning circulation (Coriolis effect).
In North America, we call a storm that results from these conditions a hurricane. In other parts of the world, a hurricane is known by other names, including "typhoon" in the Western North Pacific and "tropical cyclone" in the Indian Ocean and the Western South Pacific.

Difference between a Cyclone, Typhoon and Hurricane

People often think they are one in the same. It is confusing enough to try to keep up with the hurricane season and all the terminology, without having to decipher the difference between the three. All storms are the same after all, or are they? I found out that while they share common characteristics, they are still different. How are they different? Basically, the location is what gives the storm it's name.

If a storm was to form in the Atlantic or eastern Pacific Ocean, we would call it a hurricane. So basically every storm that endangers the United States is a hurricane. In recent years, we have all become quit familiar with hurricanes and their powerful force.

A typhoon is generally any storm that begins in the Western Pacific. So a storm that threatens Japan or the islands of Guam or the Philippines is called a typhoon. Winds from a typhoon usually are stronger than a hurricane, however they endanger far less land area due to their locations.

Cyclones are storms that begin in the Southern Pacific. They only are generated west of 160 east Longitude. They are not as prevalent as hurricanes because of the cold water temperatures. Generally, water temperature must be over 80 degrees in order to be conducive to any storm.

Recently however, there has been some controversy among the meteorological community as to the definition of a hurricane, typhoon, and cyclone. Some experts now refer to either a hurricane or a typhoon as a cyclone. Technically, when the definition of a cyclone is looked up in the dictionary, it states it is a storm with a mass of thunderstorms centered around a mass of rotating air, with an eye or center of calm air and winds, with blue skies. It states that the smaller the eye, the stronger the storm. This sounds like the definition we would attach to a hurricane.

The interesting thing that a lot of people are not aware of, is that a storm that begins north of the equator rotates clockwise and a storm that begins south of the equator rotates counterclockwise. To complicate
issues, my question has always been, can a storm cross over the equator and if so, does the rotation change? No one has been able to answer this question for me. The only answer I can get is that air currents will not allow a storm to cross over equatorial lines.

So in essence the three storms are the same. If you take a hurricane off of the coast of Florida and dump it near Japan, you have a typhoon. If you take that typhoon and drop it in the middle of the Indian ocean, it would be called a cyclone.

One thing is clear though a storm generates to the equator, the greater chance it has of being a strong storm, whether it is a typhoon or hurricane. This is due in part to the currents of the oceans, the air currents, and the water temperature. This is why typhoons are usually more dangerous than a hurricane. They generally generate closer to the equator.
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