Eye of hurricane Isabel. NOAA.
A Hurricane or Typhoon is 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. Tropical Cyclones originate over tropical or subtropical waters, with organized deep convection and a closed surface wind circulation about a well-defined center.
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.