By international agreement, tropical cyclone is the general term for all cyclone circulations originating over tropical waters, classified by form and intensity as follows:
Tropical disturbance: A moving area of thunder storms in the Tropics that maintains its identity for 24-hours or more. A common phenomenon in the tropics.
Tropical depression: Rotary circulation at surface highest constant wind speed 38 miles per hour (33 knots).
Tropical storm: Distinct rotary circulation, con stant wind speed ranges 39-73 miles per hour (34-63 knots).
Hurricane: Pronounced rotary circulation, con stant wind speed of 74 miles per hours (64 knots) or more.
Small craft cautionary statements. When a tropical cyclone threatens a coastal area, small craft operators are advised to remain in port or not to venture into the open sea.
Gale Warnings may be issued when winds of 39 54 miles an hour (34-47 knots) are expected.
Storm Warnings may be issued when winds of 55 73 miles an hour (48-63 knots) are expected. If a hurricane is expected to strike a coastal area, gale or storm warnings will not usually precede hurricane warnings.
A Hurricane Watch is issued for a coastal area when there is a threat of hurricane conditions within 24-36 hours.
A Hurricane Warning is issued when hurricane conditions are expected in a specified coastal area in 24 hours or less. Hurricane conditions include winds of 74 miles an hour (64 knots) and/or dangerously high tides and waves. Actions for protection of life and property should begin immediately when the warning is issued.
Flash Flood Watch means a flash flood is possible in the area; stay alert.
Flash Flood Warning means a flash flood is im minent; take immediate action.