The warmed air rises and is pulled into the column of clouds. Evaporation and condensation continue, building the cloud columns higher and larger. A pattern develops, with the wind circulating around a center like water going down a drain. As the moving column of air encounters more clouds, it becomes a cluster of thunderstorm clouds, called a tropical disturbance. As the thunderstorm grows higher and larger, the air at the top of the cloud column is cooling and becoming unstable.
As the heat energy is released from the cooling water vapor, the air at the top of the clouds becomes warmer, making the air pressure higher and causing winds to move outward away from the high pressure area. This movement and warming causes pressures at the surface to drop. Then air at the surface moves toward the lower pressure area, rises, and creates more thunderstorms. Winds in the storm cloud column spin faster and faster, whipping around in a circular motion.
A tropical cyclone has so many of these, they form huge, circular bands. Air from surrounding areas with higher air pressure pushes in to the low pressure area. Then that "new" air becomes warm and moist and rises, too. As the warm air continues to rise, the surrounding air swirls in to take its place. As the warmed, moist air rises and cools off, the water in the air forms clouds. The whole system of clouds and wind spins and grows, fed by the ocean's heat and water evaporating from the surface.
Storms that form north of the equator spin counterclockwise. Storms south of the equator spin clockwise. This difference is because of Earth's rotation on its axis. As the storm system rotates faster and faster, an eye forms in the center.
This happens in many other warm, tropical areas of the world too but only under certain circumstances. These storms are called hurricanes in the Atlantic and are called typhoons and tropical cyclones in other parts of the world. For one to form, there needs to be warm ocean water and moist, humid air in the region.
When humid air is flowing upward at a zone of low pressure over warm ocean water, the water is released from the air as creating the clouds of the storm.
As it rises, the air in a hurricane rotates. Air drawn into the center of a hurricane curves to the right in the Northern Hemisphere and toward the left in the Southern Hemisphere due to the Coriolis effect - a result of the Earth's rotation. Near the equator, where there is no Coriolis effect, hurricanes cannot form within miles kilometers of the equator. Storms grow if there is a continuous supply of energy from warm ocean water and warm, moist air.
Hurricane Supply Checklist: Here is a list of what what you will need if you chose to stay at your home during a hurricane. Hurricanes What is a hurricane?
A hurricane is a huge storm! It can be up to miles across and have strong winds spiraling inward and upward at speeds of 75 to mph. Each hurricane usually lasts for over a week, moving miles per hour over the open ocean. Hurricanes gather heat and energy through contact with warm ocean waters. Evaporation from the seawater increases their power.
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