As Florence lingers over the Carolinas here in the U.S., Typhoon Mangkhut is causing extensive damage in the Philippines. While the two storms may have different names and have appeared in different places, they have more in common than not.
Experts from the National Oceanic and Atmospheric Administration said typhoons and hurricanes are the same type of weather phenomenon -- tropical cyclones. A tropical cyclone is defined as any "rotating, organized system of clouds and thunderstorms that originates over tropical or subtropical waters and has closed, low-level circulation."
The weakest designation for tropical cyclones is a tropical depression. Once winds speed up to 39 mph, the storm becomes a tropical storm. Both of those terms are used globally.
The reasoning behind the differing terms for stronger tropical cyclones lies in their locations. If a tropical cyclone reaches winds at or above 74 mph, the storm is designated by a specific term, depending on where it is.
- Hurricanes are storms in the north Atlantic Ocean, central north Pacific Ocean, and eastern north Pacific Ocean. North America, Europe, South America and Central America are affected
- Typhoons are storms in the northwest Pacific Ocean.
- Storms in the south Pacific Ocean and Indian Ocean remain called tropical cyclones, regardless of their strength.
- Some parts of southwest Australia call the storms willy-willys.
All storms north of the equator rotate counterclockwise, while storms south of the equator rotate clockwise.
The World Meteorological Organization maintains the lists for all potential named storms, deciding which names are assigned where based on the region.
According to NOAA experts, 97 percent of tropical cyclone activity occurs during the Atlantic's hurricane season from June 1 to Nov. 30. However, they said that storms can develop at any time in any location.