Tropical Depression:

An organized system of clouds and thunderstorms with a defined circulation and maximum sustained winds of less than 39 mph (35 knots).

Tropical Storm:

An organized system of strong thunderstorms with a defined circulation and maximum sustained winds of 39 – 73 mph (35 – 63 knots).

Hurricane:

An intense tropical weather system with a well defined circulation and maximum sustained winds of 74 mph (64 knots) or higher.

Hurricanes are produced by the warmth and energy found in tropical atmospheres.  Gaining strength over warm seas, the storms sweep inland, bringing high tides and spawning tornadoes, torrential rains and floods.

In an average, 10 tropical storms, six of which become hurricanes, develop over the Atlantic Ocean, Caribbean Sea or Gulf of Mexico.  Many of these remain over the ocean;  however, about five hurricanes strike the United States coastline every three years.  Of these five, two will be major hurricanes, category 3 or greater on the Saffir-Simpson Hurricane Scale.

Tropical Storm Watch:

Tropical Storm conditions are possible in the specified area of the Watch, usually within 36 hours.

Tropical Storm Warning:

Tropical storm conditions are expected in the specified area of the Warning, usually within 24 hours.

Hurricane Watch:

Hurricane conditions are possible in the specified area of the Watch, usually within 36 hours.  During a Hurricane Watch, prepare to take immediate action to protect your family and property in case a Hurricane Warning is issued.

Hurricane Warning:

Hurricane conditions are expected in the specified are of the Warning, usually within 24 hours.  Complete all storm preparations and evacuate if directed by local officials.