What is a Hurricane?

Hurricanes are violent tropical storms with sustained winds of at least 74 mph. They form over warm ocean waters – usually starting as storms in the Caribbean or off the west coast of Africa. As they drift slowly westward, the warm waters of the tropics fuel them. Warm, moist air moves toward the center of the storm and spirals upward. This releases torrential rains. As updrafts suck up more water vapor, it triggers a cycle of strengthening that can be stopped only when contact is made with land or cooler water. Hurricane season is typically from June 1st to November 30th. The entire southern and eastern seaboard of the United States is at some risk for hurricanes. According to the National Oceanic and Atmospheric Administration (NOAA), 40% of hurricanes make landfall in Florida making Floridians the most at risk population to experience a deadly hurricane. Louisiana experiences the 2nd highest number of storms followed by the Carolinas.  


  • Tropical Depression - an organized system of clouds and thunderstorms with a defined circulation and maximum sustained winds of 38 mph (33 knots) or less.
  • Tropical Storm - an organized system of strong thunderstorms with a defined circulation and maximum sustained winds of 39 to 73 mph (34-63 knots).
  • Hurricane - a warm-core tropical cyclone with maximum sustained winds of 74 mph (64 knots) or greater.
  • Eye - center of a hurricane with light winds and partly cloudy to clear skies. The eye is usually around 20 miles in diameter, but can range between 5 and 60 miles.
  • Eye Wall - location within a hurricane where the most damaging winds and intense rainfall are found.


  • Category I - 74-95 mph winds with 4-5 ft. storm surge and minimal damage
  • Category II - 96-110 mph winds with 6-8 ft. storm surge and moderate damage
  • Category III - 111-130 mph winds with 9-12 ft. storm surge and major damage
  • Category IV - 131-155 mph winds with 13-18 ft. storm surge and severe damage
  • Category V - 155+ mph winds with 18+ ft. storm surge and catastrophic damage


  • Tropical Storm Watch - issued when tropical storm conditions may threaten a specific coastal area within 36 hours, and when the storm is not predicted to intensify to hurricane strength.
  • Tropical Storm Warning - winds in the range of 39 to 73 mph can be expected to affect specific areas of a coastline within the next 24 hours.
  • Hurricane Watch - a hurricane or hurricane conditions may threaten a specific coastal area within 36 hours.
  • Hurricane Warning - a warning that sustained winds of 74 mph or higher associated with a hurricane are expected in a specified coastal area in 24 hours or less.

NEXT STEPAssemble a Hurricane Survival Kit