Hurricanes are the most powerful storms on the planet. They occur over warm ocean waters around the equator. A hurricane can cause devastating damage and loss of life. Hurricanes form when air pressure differences between the equator and higher latitudes cause clouds to rotate around a horizontal axis, forming into large rotating masses called cyclones. These cyclonic winds are the cause of many tropical cyclone-related disasters.
A hurricane is a high-pressure system that develops in the tropics between Africa and South America. It forms when moisture-laden winds from the African continent collide with dry winds coming off the South American coast. This creates a region of low pressure that draws more moist air from the ocean. The combination of water vapor and low temperatures causes the air to become heavy and rise, creating the storm's high pressure center. Hurricanes usually originate from tropical depressions or tropical storms. However only about one out of every three tropical depressions becomes a hurricane. Once a depression transitions into a tropical storm or stronger, it is called a hurricane. Hurricane strength is measured by the Saffir-Simpson Scale, which rates wind speeds from 100 to 119 miles per hour as strong, 80 to 99 miles per hour as very strong, 60 to 79 miles per hour as extremely strong, and less than 60 miles per hour as intense.
Tornadoes originate over land, but hurricanes form over warm water in tropical oceans. However, both storms can change direction while traveling across the surface of the earth. Tornadoes can be anywhere in the world, but most occur in the United States. Hurricanes are destructive storms that form in the Atlantic Ocean or the Pacific Ocean. They can travel across open water as far as 5,000 miles without a land mass to absorb some of their energy.
Hurricanes are large rotating masses of air that form when an area of high pressure moves over a region of low pressure. The effect of this movement is called "cyclonic motion." If you watched a hurricane develop, you would see clouds move into its path from all directions. As these clouds collide with each other, they release their moisture into the atmosphere. This process creates rain clouds or thunderstorms. The wind from the approaching storm also causes dry vegetation to sway back and forth, which contributes to its destruction.
As a hurricane approaches a shoreline, it starts to lose strength because it runs out of places to go. Water absorbs much of the energy from the hurricane, so a coastal storm will usually not be as strong as one that is farther away from land.
Hurricanes form over the warm tropics' ocean water. When warm, wet air rises over the sea, it is replaced by colder air. The colder air will then begin to warm and ascend. Huge storm clouds arise as a result of this cycle. As the air rises, it becomes more turbulent, which increases its ability to transfer heat from the surface into its interior.
The rising air can be either hot or cold compared to the temperature of the water it is replacing. If it is cooler, moisture in the form of liquid droplets will be pulled up with it. This occurs when there are clouds above the ocean warming rapidly due to the sun's rays. The cloud droplets change to a gas at their elevated temperature and swell to many times their original size. This causes them to become heavy, which is why clouds that develop while it is raining outside are called "moisture clouds." They contain much more water than dry-ice clouds.
As the air continues to rise it reaches an altitude where it cannot hold any more moisture. At this point, any remaining droplets will fall back to earth as rain or snow. But since the air is still warm from being near the surface of the ocean, it will evaporate some of this moisture before it gets a chance to fall off of anything.
This process continues until all the moist tropical air has been raised up over the ocean.
Hurricanes are most dangerous along the Atlantic Coast, the Gulf of Mexico, and the Hawaiian Islands. They can also develop in other parts of the Pacific Ocean where there is enough water vapor from volcanic activity to form clouds that become strong enough to be classified as a hurricane. However, these storms are not as intense as hurricanes in other oceans because they do not have as much energy due to their location far from the equator.
On land, hurricanes only happen in the ocean but almost half of all hurricanes (48%) happen on land near an ocean. The majority of land-falling hurricanes occur in the Americas (73%), particularly in Central America and South America. However, the rest occur in Africa, Asia, and Oceania.
In addition to being located away from the equator, hurricanes in the Pacific tend to be weaker than those in other oceans because most of them develop over open water instead of within large bodies of water like seas or oceans. This means they have less heat absorbed from the sun that can be used to warm up air masses above the storm which would then lose some of their energy.
Land-falling hurricanes are when a hurricane makes landfall.
Hurricanes are driven toward the United States by trade winds while they are over the Atlantic near the equator. Once the storm reaches 25 or 30 degrees latitude (the top of Florida is at 30 degrees latitude), the trade winds are no longer a role, and local weather over the United States has a significant impact. The direction of the wind is called the polar vortex. It changes every six hours as a result of the earth's rotation. When it is coming from the Arctic, it is called the polar jet stream. It acts like a river, flowing in one direction across the middle of the planet. As it approaches the west coast, the flow shifts slightly to the right due to the influence of California. This shift creates the conditions for instability in the atmosphere above the storm, which leads to convection (rising air) and clouds. The storm can then evolve into a hurricane.
When a hurricane makes its way over land, it can cause major damage. Storms that make their way over the Rocky Mountains or Appalachians usually take a new direction after they cross these lines. This happens because the mountain range or forest zone is a barrier to the movement of air mass. As a result, the storm does not receive the influence of the polar vortex and begins to move in a new direction.
There are other factors that can affect the path of a hurricane. An area of low pressure can develop inside the storm and force the hurricane in another direction.