Tropical storm

Tropical storms can only form in certain parts of the world and under certain climatic conditions. They are classified according to severity - a tropical storm is not as bad as a hurricane, but worse than a tropical depression.

Tropical cyclones are classified into three main groups - tropical depressions, tropical storms, and tropical cyclones/tyhoons/hurricanes (the name of this group varies according to region).

• A tropical depression[?] is an organized system of clouds and thunderstorms with a defined surface circulation and maximum sustained winds of less than 17 metres a second (33 knot or 61 km/h or 38 mph).
• A tropical storm is an organized system of strong thunderstorms with a defined surface circulation and maximum sustained winds between 17 and 33 metres a second (34-63 knot or 63-117 km/h or 39-73 mph).
• A tropical cyclone/hurricane/typhoon has maximum sustained wind speeds exceeding 33 metres a second.

See also:

• cyclone
• hurricane
• typhoon
• subtropical cyclone