Hurricanes and typhoons are often considered two distinct weather conditions. In reality, they are the very same system. Hurricanes and typhoons are both tropical cyclones.
A tropical cyclone is composed of storms and clouds that develop over warm ocean water. This weather system rotates above the ocean water, gaining energy from the water as it circulates.
Hurricanes and typhoons are characterized as magnified tropical cyclones once the storm system forms an enclosed circle. In other words, once the storm develops an “eye” in its center, it is considered to be a tropical cyclone.
The initial stage of a tropical cyclone is called a tropical depression. Once a tropical depression reaches sustained winds of 39 miles per hour or higher, the storm’s status changes from tropical depression to tropical storm.
Once the storm reaches winds of 74 miles per hour or more, the weather system has reached the level of hurricane or typhoon. However, depending on the area in which the storm originates, the weather system may still be considered a tropical cyclone.
Tropical cyclones that reach the minimum wind speed or higher are called hurricanes in the North Atlantic, central North Pacific, and eastern North Pacific. In the Northwest Pacific, an identical storm system is called a typhoon.
Areas in the Indian Ocean and South Pacific continue to use the term ’tropical cyclone’ as a generic title without considering the wind speed of the storm.
How Tropical Cyclones Develop
For a tropical cyclone to develop, specific weather conditions must be in place. Warm ocean water, light winds, and humidity are the ideal conditions for a storm system to form.
The weather system gains energy from the moisture from the condensation of the ocean water. The water then converts into clouds and rain.
Differences Between Hurricanes and Typhoons
Hurricane season for the Atlantic Ocean typically lasts from June 1st to November 30th, with 97% of all hurricanes occurring within that time frame. With the dates serving as a guide, the storms can develop before or after the specified time.
While typhoons do not typically have a specific time frame, the majority of storm systems occur between May and October.
Another difference between hurricanes and typhoons is the direction in which the air travels.
For a hurricane, which occurs in the Northern Hemisphere, the storm system circulates in a counter-clockwise pattern. In contrast, a typhoon in the Southern Hemisphere turns toward the center in a clockwise direction.
The Main Parts of a Tropical Cyclone
A typical tropical cyclone is approximately 200 miles in diameter and consists of three separate parts. The rainbands sit around the perimeter of the storm system and typically have a radius of 100 miles. The inner radius is approximately 20 to 30 miles. The winds increase as they get closer to the center of the storm.
The eyewall is generally 10 to 20 miles from the center of the weather system. It is in this area that the winds reach their maximum speeds. The eyewall contains the eye of the storm.
The storm’s interior (or eye) is the calmest area of the storm. Wind speeds are much slower in the eye, and the air remains calm.
When the eye of the tropical cyclone reaches land, the storm has made landfall. At landfall, the weather system no longer has access to the warmth and moisture of the ocean water and begins to weaken and dissipate. The tropical storm loses size and speed as it heads further inland.
Whether called hurricanes or typhoons, a tropical cyclone is one of many dangerous weather phenomena. When a storm travels from the water onto land, it can cause injury, death, and extensive property damage each year.
However, advancements in the systems used to observe, understand, and predict the storms have resulted in improvements in prevention and preparation.
An increase in information on how the weather systems develop will result in a decrease in damage, injury, and death.