What is a Tropical Cyclone?
A tropical cyclone is a rotating, organized system of clouds and thunderstorms that originates over tropical or subtropical waters and has a closed low-level circulation. Tropical cyclones rotate counterclockwise in the Northern Hemisphere.
Tropical Depression
A tropical cyclone with maximum sustained winds of 38 mph (33 knots) or less.
Tropical Storm
A tropical cyclone with maximum sustained winds of 39 to 73 mph (34 to 63 knots).
Hurricane
A tropical cyclone with maximum sustained winds of 74 mph (64 knots) or higher.
In the western North Pacific, hurricanes are called typhoons; similar storms in the Indian Ocean and South Pacific Ocean are called cyclones.
Major Hurricane- A tropical cyclone with maximum sustained winds of 111 mph (96 knots) or higher, corresponding to a Category 3, 4 or 5 on the Saffir-Simpson Hurricane Wind Scale.
A Post-Tropical Cyclone is a system that no longer possesses sufficient tropical characteristics to be considered a tropical cyclone. Post-tropical cyclones can still bring heavy rain and high winds.
