ORLANDO, Fla.- – The “potential tropical cyclone” is a relatively new designation from the National Hurricane Center. It was created in 2017 to identify areas of disturbed weather close to land that have the potential to take on tropical characteristics.
This designation allows the National Hurricane Center to create its forecasts and issue watches and warnings, even though the storm isn’t meteorologically tropical in nature.
The main characteristic of a tropical cyclone; depression, storm or hurricane is a well-defined center at the surface. Even if the disturbance is producing winds that meet the criteria of a depression or storm, it will not be considered tropical and receive its name (once a tropical storm) unless it has that closed circulation at the surface.
I thought cyclones were in another part of the world
That’s kind of true, but cyclones do occur across the entire world. All storms are cyclones. In the Northern Hemisphere, winds spiral inward and counterclockwise. In the Southern Hemisphere, the opposite is true. A tropical cyclone is an area of low pressure in the tropics that has that well-defined center at the surface.
In our part of the world, of course, we refer to these as tropical depressions, tropical storms or hurricanes.
In the Western Pacific, once a storm has winds greater than 74 mph, it is considered a typhoon rather than a hurricane. It is still a tropical storm when it has winds below 74 mph.
In the Indian Ocean, the storms are just called cyclones.