Hurricane Terms and Meanings – What You Should Know

Hurricane season: The part of the year in which there is a relatively high incidence of hurricanes. The hurricane season in the Atlantic, Caribbean and Gulf of Mexico runs from June 1 to November 30. In the Eastern Pacific basin it runs from May 15 to November 30. Hurricane season in the Central Pacific basin runs from June 1 to November 30. Remember that this is just the hurricane season, and that hurricanes can and do occur outside of these windows.

Air pressure: Air pressure is the force exerted by air, whether compressed or unconfined, on any surface in contact with it. When more air is present over an area, a column of atmosphere has more weight, which results in high pressure. When air is removed from the column, low air pressure is the result. Hurricanes are such a powerful source of suction mainly because of their low pressure center. Typically, the rule is, the lower the pressure, the more intense the hurricane.

Cyclone: This is a blanket term for any area of low pressure that has a closed circulation. Hurricanes, tropical storms, Typhoons and tropical depressions are all cyclones because they are closed areas of low pressure.

Hurricane Watch: Sustained winds of 74 mph or higher are possible and may occur within the specified area in association with a tropical cyclone. Because hurricane preparedness activities can become difficult once winds reach tropical storm force, the hurricane watch is typically issued 48 hours before the anticipated onset of tropical-storm-force winds.

Hurricane Warning: Sustained winds of 74 mph or higher are expected to occur somewhere within a specified area in association with a tropical cyclone. The warning is typically issued 36 hours before the anticipated onset of tropical-storm-force winds.

Storm surge: This is an abnormal rise in sea levels, accompanying a hurricane or other intense storm, creating possible life-threatening situations.

Eye: Clear, sometimes well-defined center of the storm with much calmer conditions than the outer layers of the storm. The eye is either completely or partially surrounded by the eyewall cloud.

Eye Wall: The area surrounding the eye, containing some of the most severe weather of all of the storm, with the highest wind speed and largest precipitation.

Rain Bands: Bands of precipitation coming off the hurricane that produce severe weather conditions such as heavy rain, wind and tornadoes.

Indirect hit: This term generally refers to areas that do not receive a direct hit from a hurricane but do experience hurricane-force winds or tides of at least 4 feet above normal.

Tropical depression: An organized system of clouds and thunderstorms with a defined surface circulation where the maximum sustained surface wind speed is 38 mph.

Tropical disturbance: A generic term used for discrete weather systems that originate in the tropics or subtropics and maintain their form for at least 24 hours or more.

Category: You will often hear meteorologists referring to a category when discussing a hurricane. The Saffir-Simpson Hurricane Wind Scale. It is a 1 to 5 category rating system based on the hurricane’s maximum sustained wind speed. This scale estimates potential property damage in five specific categories: