A tropical cyclone is the general term for a non-frontal large scale low-pressure system over tropical or sub-tropical waters with organized thunderstorms and direct cyclonic surface wind circulation. Tropical cyclones with wind speeds less than 34 knots (39 mph) are called “tropical depressions”. If a tropical cyclone has wind speeds greater than 34 knots (39 mph), it is called a “tropical storm”. If a tropical cyclone has wind speeds greater than 64 knots (74 mph), it is called:
- "Hurricane" if it’s located in the North Atlantic Ocean, the Northeast Pacific Ocean east of the dateline, or the South Pacific Ocean east of 160°E.
- "Typhoon" if it’s located in the Northwest Pacific Ocean west of the dateline.
- "Severe tropical cyclone" or "Category 3 cyclone" and above if it’s located in the Southwest Pacific Ocean west of 160°E or Southeast Indian Ocean east of 90°E.
- "Very severe cyclonic storm" if it’s located in the North Indian Ocean.
- "Tropical cyclone" if it’s located in the Southwest Indian Ocean.
Saffir-Simpson Hurricane Wind Scale Table: