What is raw data?
Raw data is a term for data collected from a source. Raw data have not been subjected to processing or any other manipulation, and are also referred to as primary data. Raw data is a relative term (see data). Raw data can be input to a computer program or used in manual procedures such as analyzing statistics from a survey. The term can refer to the binary data on electronic storage devices such as hard disk drives (also referred to as low-level data).
Raw data, also known as source data or atomic data, is data that has not been processed in order to be displayed in any sort of presentable form. The raw form may look very unrecognizable and be nearly meaningless without processing, but it may also be in a form that some can interpret, depending on the situation. Raw data can be processed manually or by a machine.
Raw data is unprocessed computer data. This information may be stored in a file, or may just be a collection of numbers and characters stored on somewhere in the computer's hard disk. For example, information entered into a database is often called raw data. The data can either be entered by a user or generated by the computer itself. Because it has not been processed by the computer in any way, it is considered to be "raw data." To continue the culinary analogy, data that has been processed by the computer is sometimes referred to as "cooked data."
As warm, moist air over the ocean rises up from the ocean surface, there is less air left near the surface, and this causes an area of lower air pressure below. The air around this region has higher air pressure, and so it rushes in to fill the low pressure area. This air also becomes warm and moist and so it rises, too. The cycle keeps going. Warm air rises, the surrounding air swirls in to take its place, and so on. When the warm moist air rises, it cools off, and the water in the air forms clouds. The whole system of clouds and wind spins and grows, because it is being constantly fed by the ocean's heat and water evaporating from the surface.
More detailed explanation:
Cyclones (including typhoons and hurricanes) are caused by warm tropical moisture bearing clouds developing in open oceans or seas. Cyclones can only form over warm waters in the tropical regions of the oceans where the sea temperatures are 26.5 degrees Celsius or higher (around 80 degrees Fahrenheit). They occur in areas of very low pressure when air that is heated by the sun rises rapidly, and becomes saturated with moisture which then condenses into high thunderclouds. As the atmosphere becomes favorable for development (no wind shearing in the higher parts of the atmosphere), normal thunder storms clump together.
When the hot air rises, cooler air rushes in to fill the area left vacant by the hot air. The Coriolis effect of the Earth spinning on its axis causes the air to spiral upwards with considerable force. This in turn causes the winds to rotate faster, causing the tropical low to deepen in intensity into a tropical depression, and eventually a cyclone which is anywhere between hundreds of kilometres to thousands of kilometres wide.
Cyclones are also characterised by strong winds, yet in their centre is a clear, calm region called the 'eye'. When the cyclone continues its course, and the winds return from the other direction, they may seem to be more violent. The winds are not just rotating; there is also the effect of the warmer air continually rising and cold air rushing in. That is why the winds are so strong, and seem to move in all directions.
Winds gusts in a category 5 cyclone can exceed 280 kph, and a fully developed cyclone pumps out about two million tonnes of air per second.