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Terms You Should Know About Hurricanes

Tropical Depression

An organized system of clouds and thunderstorms with a defined surface circulation and maximum sustained winds of 38 MPH (33 knots) or less. Sustained winds are defined as one-minute average wind measured at about 33 ft (ten meters) above the surface.

Tropical Storm

An organized system of strong thunderstorms with a defined surface circulation and maximum sustained winds of 39–73 MPH.

Hurricane

An intense tropical weather system of strong thunderstorms with a well-defined surface circulation and maximum sustained winds of 74 MPH or higher.

Storm Surge

A dome of water pushed onshore by hurricane and tropical storm winds. Storm surges can reach 25 feet high and be 50–1000 miles wide.

Storm Tide

A combination of storm surge and the normal tide (i.e., a 15-foot storm surge combined with a two foot normal high tide over the mean sea level created a 17-foot storm tide).

Hurricane season

The part of the year having a relatively high incidence of hurricanes. The hurricane season in the Atlantic, Caribbean and Gulf of Mexico runs from June first to November 30. The season in the Eastern Pacific basin runs from May 15 to November 30. The season in the Central Pacific basin runs from June first to November 30.

Hurricane/Tropical Storm Watch

Issued when hurricane/tropical storm conditions are possible in the specified area, usually within 36 hours. Tune in to NOAA Weather Radio, commercial radio, or television for information.

Hurricane/Tropical Storm Warning

Issued when hurricane/tropical storm conditions are expected in the specified area, usually within 24 hours.

Short Term Watches and Warnings

These warnings provide detailed information about specific hurricane threats, such as flash floods and tornadoes.

Eye

The roughly circular area of comparatively light winds that encompasses the center of a severe tropical cyclone. The eye is either completely or partially (at least 50 percent) surrounded by the eye-wall cloud, an organized band or ring of cumulonimbus clouds.