Tropical Disturbance: An area of thunderstorms in the tropics that keeps its identity for 24 hours or more.
Tropical Cyclone: General term for low-pressure circulation originating over tropical waters.
Tropical Depression: A complete low pressure circulation with winds up to 38 mph (Depressions are not named, but if atropical storm weakens to a depression, it keeps its original name).
Tropical Storm: A low pressure circulation with highest sustained winds of 39-73 mph and a warm center. Storms are named.
Hurricane: A pronounced low pressure circulation with highest sustained winds of 74 mph or more and a warmcenter. Hurricanes are named.
Major Hurricane: A hurricane with highest winds of more than 110 mph.
Eye: The relatively calm area in the center of a hurricane. Eyes can range from five to more than 50 miles across.
Eye Wall: A doughnut-shaped zone of highest winds and greatest violence surrounding the eye.
Flash Flood Watch: A flash flood is possible in the area.
Flash Flood Warning: A flash flood is imminent in the area.
Tropical Storm Watch: Tropical storm conditions, including winds of 39-73 mph, are possible within 36 hours.
Tropical Storm Warning: Tropical storm conditions, including winds of 39-73 mph, are expected
Hurricane Watch: Hurricane conditions (winds of 74 mph or more and/or dangerously high water) are possible within 36 hours.
Hurricane Warning: Hurricane conditions (winds of 74 mph or more and/or dangerously high water) are expected within 24 hours.