Cyclone -- An atmospheric closed circulation rotating counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

Tropical Depression--a tropical cyclone associated with maximum sustained winds of 38 mph (33 knots) or less.

Tropical Storm--A tropical cyclone in which the maximum sustained surface wind speed (using the U.S. 1-minute average) ranges from 34 kt (39 mph or 63 km/hr) to 63 kt (73 mph or 118 km/hr). Usually associated with at least one isobar surrounding the area of lowest pressure at sealevel.

Hurricane -- A tropical cyclone in which the maximum sustained surface wind (using the U.S. 1-minute average) is 64 kt (74 mph or 119 km/hr) or more. The term hurricane is used for Northern Hemisphere tropical cyclones east of the International Dateline to the Greenwich Meridian. The term typhoon is used for Pacific tropical cyclones north of the Equator west of the International Dateline.

The name is derived from "huracan," a Taino and Carib god, or "hunraken" the Mayan storm god.