Meaning: fierce rotating winds capable of destroying all property in its path.

Fast Facts:

  • tropical storms that winds  exceed 64 knots

  • in northern hemisphere whirls in anticlockwise direction

  • in southern hemisphere whirls in clockwise direction

  • they form over water

  • the water must be over 26 degrees Celsius

  • they can last up to three weeks

  • they can cause a storm surge when they cross over onto land

  • the term "category" is used to describe the intensity of hurricanes

  • Saffir-Simpson Hurricane Scale:

    Category Wind Speeds Damage
    1 118-153km/h  * some damage to trees, shrubbery, and unanchored caravans and mobile homes
    2 154-177km/h  * major damage to caravans and mobile homes; damage buildings' roofs, and blow trees down
    3 178-209km/h  * destroy mobile homes; blow down large trees; damage small buildings
    4 210-248km/h  * completely destroy caravans and mobile homes; lower floors of structures near shore are susceptible to flooding
    5 above 248km/h  * extensive damage to homes and industrial buildings; blow away small buildings; lower floors of structures within 500 meters of shore and less than 5 metres above sea level are damaged


    Flooding caused by Hurricane Katrina in the New Orleans area is visible from Air Force One Wednesday, Aug. 31, 2005 as President Bush returned to Washington from Crawford Texas.

    Source: White House photo by Paul Morse

    Two images of the w:Chandeleur Islands off the coast of Louisiana, USA. The left image is from 2004 and the right is from 2005, after Hurricane Katrina.

    Photo by Jesse Allen, NASA Earth Observatory, using data provided courtesy of Laura Rocchio, NASA Landsat Project Science Office.