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Hurricane Facts and Terms

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Tropical Depression
An organized system of clouds and thunderstorms with a defined surface circulation and maximum sustained winds of 38 MPH or less.
 
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.
 
Hurricane/Tropical Storm Watch
Hurricane/tropical storm conditions possible in the specified area, usually within 36 hours.
 
Hurricane/Tropical Storm Warning
Hurricane/tropical storm conditions expected in the specified area, usually within 24 hours.
 
Tornado
Appears as a rotating, funnel-shaped cloud that extends from a thunderstorm to the ground with whirling winds that can reach 300 MPH.
 
Tornado Watch
Tornado is possible.
 
Tornado Warning
Tornado has been sighted or indicated by weather radar.
 
Storm Surge
A dome of water pushed onshore by hurricane and tropical storm winds; can reach 25 feet high and be 50-100 miles wide.
 
Sustained winds
A one-minute average wind measured at about 33 feet above the surface.
 
Sources: Federal Emergency Management Agency (FEMA), NOAA National Hurricane Center