What Is A Hurricane?
A hurricane is a categorization of a tropical cyclone, occurring in tropical and subtropical waters. These natural disasters begin as a collection of rain clouds over warm waters. This weather disturbance can grow into rotating thunderstorms. When their winds reach 74 miles per hour (mph), they are classified as hurricanes. Hurricanes can reach over 157 miles per hour. On screen, these storms are recognized by their swirling figure and hole-like center area, called the eye.
The Parts Of A Hurricane
Rain bands extend for hundreds of miles around the storm, carrying rain, clouds, thunderstorms, and sometimes tornadoes. This is the hurricane area of that begins to move in a circular motion around the rest of the storm. Closer to the center is the eyewall, which begins to form as the storm becomes stronger due to the formation of convection and upward-moving air. This eyewall is where the winds are strongest and heavy thunderstorms occur. In the very center of the storm is the eye of the hurricane. In fact, it is the formation of the eye of a hurricane that allows weather forecasters and meteorologists to determine that the hurricane is gaining strength. The eye appears clear with few clouds and has lower wind speeds than the rest of the hurricane. However, it is not as calm as it appears.
Inside The Eye Of A Hurricane
The eye of the hurricane is usually between 20 and 40 miles in diameter, although some have been recorded at 120 miles. When this part of the hurricane hits land, it is the calmest area inside of the storm. In fact, people often think the storm has passed and go outside only to be caught by the approaching eyewall. Over water, however, the eye of a hurricane is one of the most dangerous places to be. Inside the eye of a hurricane, waves are tossed around by strong winds. These waves can reach as high as 130 feet. Within its area, temperatures are often 18° warmer and surface pressure is at its lowest. The air inside of the eye slowly sinks while the air of the eyewall rises.
Formation Of The Eye
Researchers have yet to agree on exactly how the eye of a hurricane is formed. One commonly accepted theory is that it is the result of the downward-moving pressure weakening the winds. Another theory suggests that the eye of the hurricane is the result of energy released by the eyewall which pushes down the air within the center. One thing is clear, however. As the air moves down, it compresses and heats up. As this occurs, the water below the eye becomes buoyant, moving up and creating waves. The eye of the hurricane is ultimately what allows the hurricane to achieve such high wind speeds. Occasionally, the rainbands become so intense that they form an additional eyewall within the hurricane. The second eyewall grows and eventually consumes the previous one. This process is called an eyewall replacement cycle.
Other Storms With Eyes
Eye-like formations occur in other weather patterns that have similar cyclone shapes. The first of these is a polar low. This phenomenon is similar to a tropical storm, but forms in very cold waters. It has an eye and rainbands that produce large amounts of snow and ice. Other storms with similar formations include extratropical cyclones, subtropical cyclones, and tornadoes.