One symptom of climate change is more severe tropical cyclones, hurricanes and typhoons, featuring in the headlines more often.
What is a tropical cyclone?
A tropical cyclone is a generic term for a small, intensely developed low-pressure cell that forms over warm oceans. Its diameter can range from 200km to 2,000km, with a warm centre and strong cyclonic winds, moving clockwise in the southern hemisphere.
What is a tropical depression?
Tropical cyclones with a maximum wind speed of less than 60km per hour are called tropical depressions.
What is a tropical storm?
When a tropical cyclone reaches speeds ranging from 60km per hour to 110km per hour it is called a tropical storm and given a name.
What is the difference between a hurricane, a typhoon and a tropical cyclone?
"Hurricane" and "typhoon" are regionally specific names for a strong tropical cyclone.
When wind speeds reach more than 119km per hour, a tropical cyclone is called:
- a "hurricane" over the North Atlantic Ocean, the Northeast Pacific Ocean east of the International Date Line or the South Pacific Ocean east of 160°E
- a "typhoon" over the Northwest Pacific Ocean, west of the International Date Line
- "severe tropical cyclone" over the Southwest Pacific Ocean west of 160°E or Southeast Indian Ocean east of 90°E
- "severe cyclonic storm" over the north Indian Ocean
- "tropical cyclone" over the southwest Indian Ocean
The Atlantic Oceanographic and Meteorological Laboratory
The South African Weather Service
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