Changes

Hurricanes require a special set of conditions, including ample [[heat]] and [[moisture]] that exist primarily over warm tropical oceans. For a hurricane to form, there must be a warm layer of water at the top of the sea with a surface temperature greater than 80 degrees [[Fahrenheit]]. Warm seawater evaporates and is absorbed by the surrounding air. The warmer the ocean, the more water evaporates. The warm, moist air rises, lowering the atmospheric pressure of the air beneath. In any area of low atmospheric pressure, the column of air that extends from the surface of the water or land to the top of the atmosphere is relatively less dense and therefore weighs relatively less.

Hurricanes require a special set of conditions, including ample [[heat]] and [[moisture]] that exist primarily over warm tropical oceans. For a hurricane to form, there must be a warm layer of water at the top of the sea with a surface temperature greater than 80 degrees [[Fahrenheit]]. Warm seawater evaporates and is absorbed by the surrounding air. The warmer the ocean, the more water evaporates. The warm, moist air rises, lowering the atmospheric pressure of the air beneath. In any area of low atmospheric pressure, the column of air that extends from the surface of the water or land to the top of the atmosphere is relatively less dense and therefore weighs relatively less.

Since [[air]] tends to move from areas of high pressure to areas of low pressure, creating wind. In the Northern Hemisphere, the earth's rotation causes the wind to swirl into a low-pressure area in a [[counterclockwise]] direction. This effect of the rotating earth on wind flow is called the [[Coriolis effect]]. The Coriolis effect increases in intensity farther from the equator. To produce a hurricane, a low-pressure area must be more than 5 degrees of latitude north of the equator. Hurricanes seldom occur closer to the equator. For a hurricane to develop, there must be little wind shear, or in other words, little difference in [[speed]] and direction between winds at upper and lower elevations. Uniform winds enable the warm inner core of the storm to stay intact. The storm would break up if the winds at higher elevations increased markedly in speed, changed direction, or both. The wind shear would disrupt the budding hurricane by tipping it over or by blowing the top of the storm in one direction while the bottom moved in another direction.  

Since [[air]] tends to move from areas of high pressure to areas of low pressure, creating wind. In the Northern Hemisphere, the earth's rotation causes the wind to swirl into a low-pressure area in a [[counterclockwise]] direction. This effect of the rotating earth on wind flow is called the [[Coriolis effect]]. The Coriolis effect increases in intensity farther from the equator. To produce a hurricane, a low-pressure area must be more than 5 degrees of latitude north of the equator. Hurricanes seldom occur closer to the equator. For a hurricane to develop, there must be little wind shear, or in other words, little difference in [[speed]] and direction between winds at upper and lower elevations. Uniform winds enable the warm inner core of the storm to stay intact. The storm would break up if the winds at higher elevations increased markedly in speed, changed direction, or both. The wind shear would disrupt the budding hurricane by tipping it over or by blowing the top of the storm in one direction while the bottom moved in another direction.