Hurricane Terminology

Hurricane Terms, Courtesy of National Oceanic and Atmospheric Administration (NOAA). 

Category One - Winds of 74-95 mph. Damage primarily to unanchored mobile homes, power lines and trees. Example: Hurricane Irma, 2017.

Category Two - Winds 96-110 mph. Some damage to roofs, doors and windows. Considerable damage to trees, mobile homes, small boats in unprotected anchorages and piers. Example: Hurricane Wilma, 2005.

Category Three - Winds 111-130 mph. Some structural damage to homes and buildings. Heavy damage/destruction of trees and mobile homes. Example: Hurricane Frances, 2004

Category Four - Winds 131-155 mph. More extensive roof damage on small homes. Shrubs, trees and all signs are blown down. Complete destruction of mobile homes. Extensive damage to doors and windows. Low-lying escape routes may be cut by rising water three to five hours before the arrival of the center of the hurricane. Example: Hurricane Charley, 2004.

Category Five - Winds greater than 155 mph. Complete roof failure on many residences and industrial buildings. All shrubs, trees and signs blown down. Complete destruction of mobile homes. Severe and extensive window and door damage. Low-lying escape routes are cut by rising water three to five hours before the arrival of the center of the hurricane. Major damage to lower floors of all structures located less than 15 feet above sea level and within 500 yards of the shoreline. Example: Hurricane Andrew, 1992.

Evacuation - A warning to persons who may be at risk, due to location or other vulnerabilities, within a designated area that a threat to life and property may be imminent and they should move to a safer location as directed by emergency management officials.

Hurricane - A tropical system with maximum sustained winds of 74 mph or higher.

Hurricane Eye - The calm center of the storm that is often only partly covered by clouds.

Hurricane Warning - A warning that hurricane conditions, including sustained winds of 74 mph or higher, are imminent within 36 hours or less.

Hurricane Watch - An announcement that hurricane conditions, including sustained winds of more than 74 mph, are possible within 48 hours.

Mandatory Evacuation - A notification to persons within a designated area (evacuation zone) that an imminent threat to life and property exists. Individuals MUST relocate and seek refuge in an inland, non-evacuation area.

Saffir-Simpson Scale - Assigns hurricanes to one of five categories based on a storm's wind speed and damage potential.

Storm Surge - An abnormal rise in sea level accompanying a hurricane or other intense storm that's caused by storm's barometric pressure, forward speed and wind intensity. Surge can be anywhere from a few feet to 18 feet along South Florida coasts. Storm Surge watches and warnings are issued to the public by the National Hurricane Center.

Storm Surge Watch - The possibility of life-threatening inundation of rising water moving inland from the shoreline within the specified areas within 48 hours.

Storm Surge Warning - The possibility of life-threatening inundation of rising water moving inland from the shoreline within the specified areas within 36 hours.

Tropical Depression - A tropical system with maximum sustained winds of 38 mph or less. Tropical depressions can produce heavy rainfall.

Tropical Storm - A tropical system with sustained winds of 39-78 mph. A tropical storm can produce heavy rainfall and strong winds.

Tropical Storm Warning - A warning that tropical storm conditions, including sustained winds of 39-73 mph, are imminent within 36 hours.

Tropical Storm Watch - An announcement that tropical storm conditions, including sustained winds of 39-73 mph, are possible within 48 hours.