Hurricane season is already in full swing – with us luckily bypassing Hurricane Florence a few weeks ago. In order to be as prepared as possible, we wanted to compile the most important hurricane terms that everyone should know, in order to best prepare themselves. All information found through the National Hurricane Center.
A tropical cyclone in which the maximum sustained surface wind speed ranges from 39 MPH to 73 MPH.
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.
A hurricane that is classified as Category 3 or higher.
- Category 1 – 74-95 MPH
- Category 2 – 96-110 MPH
- Category 3 – 111-129 MPH
- Category 4 – 130-156 MPH
- Category 5 – 157 MPH or higher
An atmospheric closed circulation rotating counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
Landfall refers to the intersection of the surface center of a tropical cyclone with a coastline. Because the strongest winds in a tropical cyclone aren’t located precisely at the center, it’s possible for the strongest winds to be experienced on land, even if landfall hasn’t happened yet. It’s also possible for a tropical cyclone to make landfall and have its strongest winds still remain over the water.
A close approach of a tropical cyclone to a geographic location. For locations on the left-hand side of a cyclone’s track, a direct hit occurs when the cyclone passes within a distance equal to the cyclone’s radius of maximum wind. For locations on the right-hand side of the track, a direct hit occurs when the cyclone passes to within a distance equal to twice the radius of maximum wind.
Refers to the location that doesn’t experience a direct hit from a cyclone, but does experience hurricane force winds or tides of at least 4 feet above average.
The area in which a hurricane may most tremendously impact. Usually, the government and emergency management will make an announcement stating that residents of these zones must evacuate before a certain time before the storm hits. If they don’t, emergency teams will not be able to rescue you if you are in danger until it is safe enough to do so. These zones are often close to coastlines.
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.
An announcement that sustained winds of 74 MPH or higher are expected somewhere within the specified area of association with a tropical, subtropical or post-tropical cyclone. The warning is usually issued 36 hours in advance of the anticipated onset. 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.
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’ve occurred on a normal day.
Eye of the Storm
The circular area of comparatively light winds that sit inside the center of a severe tropical cyclone. The eye is either completely or partially surrounded by the eyewall cloud.
An organized band or ring of cumulonimbus clouds that surround the eye, or high-wind center of a tropical cyclone.
These are usually referred to as “feeder” or “spiral” bands, which sit outside of the eyewall that keeps the hurricane filled with force and continuously moving. These make up the largest part of the storm.
The pressure exerted by the weight of the atmosphere, which drops to very low levels at the ocean’s surface. This low pressure creates moist ocean air and the formation of thunderstorms around it.
*Info from National Hurricane Center.