Here’s what the most common hurricane terms actually mean

A hurricane strikes a Florida beach.

New to Florida or the terms that start to fly around during hurricane season?

The Atlantic hurricane season runs from June 1 through Nov. 30, with the most active period being from mid-August to late October, according to the National Oceanic and Atmospheric Administration.

Here’s an explanation of some of the most common terms you could see, provided by News 6 partner Florida Today:

Tropical depression: A tropical cyclone in which the maximum sustained surface wind speed is 38 mph or less.

Tropical storm: A tropical cyclone in which the maximum sustained surface wind speed ranges from 39 mph to 73 mph.

Hurricane/typhoon: A tropical cyclone in which the maximum sustained surface wind is 74 mph 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.

Major hurricane: A hurricane that is classified as Category 3 or higher. Sustained winds would be 111 mph or higher.

The hurricane wind speeds associated with the Saffir-Simpson Scale used by the National Hurricane Center.

Landfall: The intersection of the surface center of a tropical cyclone with a coastline. Because the strongest winds in a tropical cyclone are not located precisely at the center, it is possible for a cyclone’s strongest winds to be experienced over land even if landfall does not occur. Similarly, it is possible for a tropical cyclone to make landfall and have its strongest winds remain over the water. Compare direct hit, indirect hit, and strike.

Storm surge: An abnormal rise in sea level accompanying a hurricane or other intense storm, and whose height is the difference between the observed level of the sea surface and the level that would have occurred in the absence of the cyclone.

Storm surge is usually estimated by subtracting the normal or astronomic high tide from the observed storm tide.

Watches and warnings

Hurricane watch: An announcement that sustained winds of 74 mph or higher are possible within the specified area in association with a tropical, subtropical, or post-tropical cyclone.

Because hurricane preparedness activities become difficult once winds reach tropical storm force, the hurricane watch is issued 48 hours in advance of the anticipated onset of tropical storm force winds.

Hurricane warning: An announcement that sustained winds of 74 mph or higher are expected somewhere within the specified area in association with a tropical, subtropical, or post-tropical cyclone.

Because hurricane preparedness activities become difficult once winds reach tropical storm force, the warning is issued 36 hours in advance of the anticipated onset of tropical-storm-force winds.

The warning can remain in effect when dangerously high water or a combination of dangerously high water and waves continue, even though winds may be less than hurricane force.

Tropical storm watch: An announcement that sustained winds of 39 to 73 mph are possible within the specified area within 48 hours in association with a tropical, subtropical, or post-tropical cyclone.

Tropical storm warning: An announcement that sustained winds of 39 to 73 mph are expected somewhere within the specified area within 36 hours in association with a tropical, subtropical, or post-tropical cyclone.

Storm surge watch: The possibility of life-threatening inundation from rising water moving inland from the shoreline somewhere within the specified area, generally within 48 hours, in association with an ongoing or potential tropical cyclones, a subtropical cyclone or a post-tropical cyclone.

The watch may be issued earlier when other conditions, such as the onset of tropical-storm-force winds are expected to limit the time available to take protective actions for surge (e.g., evacuations). The warning may also be issued for locations not expected to receive life-threatening inundation but which could potentially be isolated by inundation in adjacent areas.

Storm surge warning: The danger of life-threatening inundation from rising water moving inland from the shoreline somewhere within the specified area, generally within 36 hours, in association with an ongoing or potential tropical cyclones, a subtropical cyclone or a post-tropical cyclone.

The warning may be issued earlier when other conditions, such as the onset of tropical-storm-force winds are expected to limit the time available to take protective actions for surge (e.g., evacuations). The warning may also be issued for locations not expected to receive life-threatening inundation but which could potentially be isolated by inundation in adjacent areas.


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