This section explains some of the key terms that will help you better understand hurricane-related terminology used in Historical Weather Risk.
Extratropical cyclone: Any cyclone not of tropical origin. Generally considered to be a migratory frontal cyclone found in the middle and high latitudes.
Tropical depression: A tropical cyclone in which maximum sustained surface winds are 38 miles per hour or less. Tropical depressions typically have closer isobars and can evolve into tropical storms or hurricanes.
Tropical storm: A tropical cyclone with maximum sustained winds between 39 and 73 miles per hour.