weather [forecasting]

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WEATHER INSTRUMENTS

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Weather forcasting In order to predict the weather, meteorologists constantly gather information about weather conditions everywhere on Earth. This information is collected using specialized equipment. A barometer measures atmospheric pressure, a thermometermeasures the temperature, and an anemometer measures wind speed and direction. Weather radar detects precipitation in the clouds, and the Doppler radar takes measurements of winds in clouds in order to predict severe storms and tornadoes. All of these measurements help scientists make an accurate weather forecast. Weather stations often contain the different weather instruments listed above to collect data. In addition, scientists launch weather balloons to collect data from the atmosphere. Research aircraft also carry Thunderstorms Hurricanes Tornadoes Thunderstorms are one of the most thrilling and dangerous types of weather phenomena. Over 40,000 thunderstorms occur throughout the world each day. Thunderstorms form when very warm, moist air rises into cold air. As this humid air rises, water vapor condenses, forming huge cumulonimbus clouds. There are two main types of thunderstorms: ordinary and severe. Ordinary thunderstorms are the common summer storm and usually last about one hour. The precipitationassociated with these storms includes rain and occasionally small hail. With ordinary thunderstorms, cumulonimbus clouds can grow up to 12 kilometers high. Severe thunderstorms are very dangerous. They are capable of producing baseball-sized hail, strong winds, intense rain, flash floods, and tornadoes. Severe thunderstorms can last several hours and can grow 18 kilometers high. Several phenomena are associated with severe thunderstorms, including gust fronts, microbursts, supercell thunderstorms, and the squall lines. Tornadoes form from severe thunderstorms. They have a very high energy density which means that they affect a small area but are very destructive to that area. They also don't last very long which makes it hard to learn about them. Since they're hard to study, they're also hard to forecast. People know even less about tornadoes, which is why there are a lot of different myths that aren't true. Tornadoes can occur anywhere in the world. About 75% of them happen in the United States, most in an area know as Tornado Alley. There are also some other interesting facts about tornadoes. People who are interested in tornadoes sometimes become trained tornado spotters for their community. Others chase tornadoes, either to research these incredible storms, or to photograph them. After a tornado touches down, scientists try and figure out how strong it was by using the Enhanced Fujita Tornado Scale. As a strong hurricane heads towards the coast, people prepare - boarding up houses, packing the car, and evacuating. These storms can spell disaster for people in hurricane prone areas, so they are taken very seriously. They are the most powerful of all weather systems and they are huge - an average of 340 miles across. Hurricanes form in the tropics over warm ocean water and die down when they move over land or out of the tropics. These storms are called hurricanes in the Atlantic and typhoons or tropical cyclones in other areas of the world. In the Northern Hemisphere the storms rotate counterclockwise and in the Southern Hemisphere they rotate clockwise because of the Coriolis Effect. At the center of the rotating storm is a small area of calm weather and clear skies called the eye. Hurricane damage in coastal areas is often due to storm surge, which floods coastal areas. Strong wavesand wind also batter coastal areas. Hurricanes also cause a tremendous amount of rain. Not all storms are the same. Large and strong storms cause much more damage than small storms. In the Atlantic and Eastern Pacific, the Saffir-Simpson Hurricane Scale is used to describe the size of a hurricane. As hurricanes move, scientists try to forecast where and when the storm will reach land in order to warn people. Hurricanes are tracked over large distances with weather satellites. Computer models that take into account factors of the storm and the atmosphere are used to predict where the storm will go. Since 1953 each hurricane has been given a name to help warn people that a storm was on its way. Hurricanes usually happen at a particular time of year called hurricane season. The timing of hurricane season is different in different regions of the world. In the North Atlantic, hurricane season is from June 1st to November 30th each year. Weather forcasting In order to predict the weather, meteorologists constantly gather information about weather conditions everywhere on Earth. This information is collected using specialized equipment. A barometer measures atmospheric pressure, a thermometermeasures the temperature, and an anemometer measures wind speed and direction. Weather radar detects precipitation in the clouds, and the Doppler radar takes measurements of winds in clouds in order to predict severe storms and tornadoes. All of these measurements help scientists make an accurate weather forecast. Weather stations often contain the different weather instruments listed above to collect data. In addition, scientists launch weather balloons to collect data from the atmosphere. Research aircraft also carry