Tropical storm

From Glossary of Meteorology



tropical storm

A stage of a tropical cyclone between initially developing a closed circulation (e.g., tropical depression) and a mature tropical cyclone (e.g., hurricane and typhoon), with differences in terminology based on ocean basin.

In the Western Hemisphere, it is a tropical cyclone with a closed wind circulation and maximum surface winds of 18–32 m s−1 (35–64 knots; kt).

In the northwestern Pacific Ocean, it is a tropical cyclone with maximum surface winds of 18–24 m s−1; a tropical cyclone with maximum surface winds of 24–32 m s−1 is referred to as a severe tropical storm.

In the northern Indian Ocean, these two classes are referred to as cyclonic storms and severe cyclonic storms, respectively.

In the southwestern Indian Ocean, they are referred to as moderate tropical storms and severe tropical storms, respectively.

For a more complete discussion, see tropical cyclone.


Term edited 15 December 2022.


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