How do cyclones affect the weather

Air converges into a low pressure center which causes air to rise. The rising motion may produce clouds and precipitation. Different precipitation types include rain and thunderstorms in the summer and fall seasons, to rain, thunderstorms, and even snow during the winter. A low is represented on a weather map by a red "L". In the tropics there is a broad zone of low pressure which stretches either side of the equator.

The winds on the north side of this zone blow from the north-east the north-east trades and on the southern side blow from the south-east south-east trades.

Within this area of low pressure the air is heated over the warm tropical ocean. This air rises in discrete parcels, causing thundery showers to form. These showers usually come and go, but from time to time, they group together into large clusters of thunderstorms. This creates a flow of very warm, moist, rapidly rising air, leading to the development of a centre of low pressure, or depression, at the surface.

There are various trigger mechanisms required to transform these cloud clusters into a tropical cyclone. These trigger mechanisms depend on several conditions being 'right' at the same time. The most influential factors are:. The Coriolis force caused by the rotation of the Earth helps the spin of this column of rising air. The development of the surface depression causes an increase in the strength of the trade winds.

The spiralling winds accelerate inwards and upwards, releasing heat and moisture as they do so. As the depression strengthens it becomes a tropical storm and then a hurricane or typhoon. A mature hurricane or typhoon takes the form of a cylinder of deep thundercloud around a centre that is relatively free from clouds. There is a relatively small area of intense horizontal winds at the surface, often well over m. Further aloft at about six miles, the cloud tops are carried outwards to give thick layer clouds due to the outward-spiralling winds leaving the tropical cyclone core.

At the centre of the tropical cyclone, air is subsiding, which makes it dry and often cloud free, and there is little or no wind at the surface. This is called the eye of the storm. Great amounts of energy are transferred when warm water is evaporated from tropical seas. This energy is stored within the water vapour contained in moist air. The release of heat energy warms the air locally, causing a further decrease in pressure aloft. Consequently, air rises faster to fill this area of low pressure, and more warm, moist air is drawn off the sea, feeding further energy to the system.

Thus, a self-sustaining heat engine is created. This relatively small amount of mechanical energy equates to a power supply of 1. Tropical cyclones are named to provide ease of communication between forecasters and the general public, regarding forecasts, watches and warnings.

Since the storms can often last a week or even longer, and more than one can be occurring in the same region at the same time, names can reduce the confusion about what storm is being described. Names were first used widely in World War II and were subsequently adopted by all regions. In most regions pre-determined alphabetic lists of alternating male and female names are used. However, in the western North Pacific and North Indian Oceans the majority of names used are not personal names.

While there are a few male and female names, most are names of flowers, animals, birds, trees, foods or descriptive adjectives. The names are also not allocated in alphabetical order, but are arranged by the name of the Asian country which contributed the name.

Many tropical cyclones eventually drift far enough from the equator to move into areas dominated by westerly winds found in the middle latitudes. These winds tend to reverse the direction of the tropical cyclone to an eastward path. As the tropical cyclone moves polewards it picks up forward speed and may reach 30 m.

An average tropical cyclone can travel about to miles a day, or about 3, miles before it dies out. Tropical cyclones also occur in various parts of the Pacific Ocean, and can affect coastal regions of Mexico, south-east Asia, north-east Australia and the south Pacific islands. In the northern hemisphere most tropical cyclones occur between June and November with a peak in September. However, in the western North Pacific it is not unusual to have the occasional tropical cyclone outside of this period.

In the southern hemisphere the season usually lasts from November to April. Tropical cyclones are occasionally observed in the South Atlantic, but this is a very rare occurrence. The map above shows the areas of the world affected by tropical cyclones. Past tropical cyclones. Other phenomena which can be just as damaging than the wind frequently accompany tropical cyclones:.

These phenomena can cause major destruction, especially when the tropical cyclone's path takes it over land. Behind a passing cold front, you will encounter rapidly clearing skies and falling temperatures. Tropical cyclones, also known as tropical storms and hurricanes, are a special type of low-pressure system.

These systems are non-frontal, meaning they are not associated with cold or warm fronts. Rather than mixing cold and warm air masses, they are uniformly warm and moist. Tropical cyclones also combine very low pressures with small size, producing very strong winds and strong vertical cloud development. Finally, even after these tropical cyclones move inland and their winds subside, they can dump large amounts of rainfall, leading to dangerous flooding.

Doug Bennett has been researching and writing nonfiction works for more than 20 years. His books have been distributed worldwide and his articles have been featured in numerous websites, newspapers and regional publications. Warm Front Characteristics.

The Three Types of Weather Fronts. The Stages of Mid-Latitude Cyclones. What Causes a Tropical Revolving Storm? The Effects of a Cyclone.