Answers to Questions about Hurricanes



The how, what, where, when, and why of hurricanes and tropical weather


  • What is the definition of a tropical depression, tropical storm, and hurricane?

  • Tropical Depression - A tropical cyclone in which the maximum sustained surface wind speed is 38 mph or less.
    Tropical Storm - A tropical cyclone in which the maximum sustained surface wind speed ranges from 39 mph to 73 mph.
    Hurricane - A tropical cyclone in which the maximum sustained surface wind is 74 mph or more.


  • What is the definition of a tropical cyclone, subtropical cyclone and extratropical cyclone?

  • Tropical Cyclone
    A warm-core non-frontal synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and a closed surface wind circulation about a well-defined center. Once formed, a tropical cyclone is maintained by using heat energy from the ocean. In this they differ from extratropical cyclones, which derive their energy from horizontal temperature contrasts in the atmosphere (baroclinic effects).


    Extratropical Cyclone
    A term used in advisories and tropical summaries to indicate that a cyclone has lost its "tropical" characteristics. The term implies both poleward displacement of the cyclone and the conversion of the cyclone's primary energy source from the release of latent heat of condensation to baroclinic (the temperature contrast between warm and cold air masses) processes. It is important to note that cyclones can become extratropical and still retain winds of hurricane or tropical storm force.


    Subtropical Storm
    A subtropical cyclone in which the maximum sustained surface wind speed is 39 mph or more.


  • How do you forecast hurricanes?

  • Click here for more details.

  • What is the difference between a hurricane and a typhoon?

  • A hurricane and typhoon are the same. They are simply tropical cyclones that form in different parts of the world. The term hurricane is used in the north Atlantic ocean, the north Pacific (east of the dateline) and the south Pacific (east of 160E). The term typhoon is used in the northwest Pacific ocean (west of 160E) and southeast Indian Ocean (east of 90E). In addition to the names "hurricane" and "typhoon", severe tropical cyclone is used in the southwest Pacific ocean (west of 160E) and southeast Indian Ocean (east of 90E).
    Tropical cyclone is the name used in the southwest Indian Ocean and severe tropical cyclone is used in the southwest Indian Ocean.


  • In what part of the world do hurricanes form?

  • Hurricanes can form in the tropical or subtropical oceans around the whole world. Tropical cyclones can form in any part of the world where the right conditions exist for them to develop. The Atlantic, Pacific, and Indian Oceans have the right conditions for tropical cyclones to develop.

  • When is hurricane season?

  • Click here for more information. Check bottom of article.

  • How are hurricanes named?

  • 1950-1952-In the North Atlantic, the naming of tropical cyclones officially started in 1950. For the first two years tropical cyclones were given names based on the phonetic alphabet. (A - able, B - Baker, C - Charlie, D - Dog and so on)
    1953-1978-Starting in 1953 the US Weather Bureau changed from the phonetic alphabet to women's names. They came up with six different lists of namesto be rotated, one list each year.
    1979-now-In 1979 the World Meteorological Organization and the National Weather Service decided to add mens names to the lists. Womens and mens names are rotated on the lists.


  • Why are some hurricane names not used any longer?

  • When a hurricane causes great damage or cost the name is retired. The World Meteorological Organization votes on a replacement name.

  • What is the difference between a hurricane watch and a hurricane warning?

  • Hurricane Watch-An announcement that sustained winds of 64 knots (74 mph or 119 km/hr) or higher are possible within the specified area in association with a tropical, subtropical, or post-tropical cyclone. Because hurricane preparedness activities become difficult once winds reach tropical storm force, the hurricane watch is issued 48 hours in advance of the anticipated onset of tropical storm force winds.


    Hurricane Warning-.
    An announcement that sustained winds of 64 knots (74 mph or 119 km/hr) or higher are expected somewhere within the specified area in association with a tropical, subtropical, or post-tropical cyclone. Because hurricane preparedness activities become difficult once winds reach tropical storm force, the warning is issued 36 hours in advance of the anticipated onset of tropical-storm-force winds. The warning can remain in effect when dangerously high water or a combination of dangerously high water and waves continue, even though winds may be less than hurricane force.

  • What can you do to prepare for a hurricane?

  • Check our hurricane preparedness page for more information.

  • Where do hurricanes occur in the world?

  • Click here for more information.

  • What are the different effects of a hurricane?

  • 1. Storm Surge - This is the water that is "piled up" ahead of a hurricane because of the strong winds blowing over the ocean. The low pressure has a very minimal effect on storm surge. The surge is what inudates coastal areas with flooding.
    2. Tornadoes - They are usually found in spiral bands in the right front quadrant relative to motion.
    3. Wind Damage - The strongest winds are found in the eyewall of a hurricane. Squalls are also found in the spirial bands. Winds can gust to more than 200 mph in the strongest hurricanes.
    4. Inland Flooding - This is not flooding caused by surge, but by heavy rainfall. This is especially true with slow moving tropical cyclones.


  • Who are the Hurricane Hunters?

  • They are the men and women of the the 53rd Weather Reconnaissance Squadron of the Air Force Reserve, based at Keesler Air Force Base in Biloxi, Mississippi.
    They fly into tropical cyclones to send important hurricane information to the National Hurricane Center. Information such as temperature, barometric pressure, wind speed and direction are measured.


  • Does Global Warming affect hurricanes?

  • Read more about global warmings effect on hurricanes.

  • How do hurricanes form?

  • Article on how hurricanes form.

  • What causes hurricanes?

  • Here is more information on the causes of hurricanes.

  • What causes typhoons?

  • Click here for more about the causes for typhoons.

  • Could a category 5 hurricane hit New York City?

  • Read the article here.

The Deadliest, Costliest and Most Intense Hurricanes

Atlantic Category 5 Hurricanes
Rank Hurricane Name Year Top Sustained Winds
1 Allen 1980 190 mph
2 Wlima 2005 185 mph
2 Gilbert 1998 185 mph
2 "Keys Labor Day" 1935 185 mph
3 Rita 2005 180 mph
3 Mitch 1998 180 mph
4 "Cuba" 1932 175 mph
4 Dean 2007 175 mph
4 Katrina 2005 175 mph
4 Andrew 1992 175 mph
4 David 1979 175 mph
4 Anita 1977 175 mph
4 Camille 1969 175 mph
4 Carla 1961 175 mph
4 Janet 1955 175 mph
4 "Cuba" 1932 175 mph
5 Ivan 2004 165 mph
5 Isabel 2003 165 mph
5 "Cuba" 1924 165 mph
6 Emily 2005 160 mph
6 Hugo 1989 160 mph
6 Edith 1971 160 mph
6 Beulah 1967 160 mph
6 Hattie 1961 160 mph
6 Donna 1960 160 mph
6 Ethel 1960 160 mph
6 Cleo 1958 160 mph
6 Carol 1953 160 mph
6 "Long Island Express" 1938 160 mph
6 "Tampico" 1933 160 mph
6 "Cuba - Brownsville" 1933 160 mph
6 Bahamas 1932 160 mph
6 "San Felipe 2 - Okeechobbe" 1924 160 mph


The Structure of Hurricanes

  • What are the different parts that make up a hurricane?

  • There are number of basic parts to a hurricane.

    1. The Eye - The most notable part of a hurricane. The eye is located at the center of a hurricane. It is where winds are sinking and calm or nearly calm. Air pressure is at its lowest in the eye. Skies are usually fair with only a few clouds. Sometimes high cirrus clouds obscure the eye so that it is not visible on satellite pictures. The eye is usually circular, but can be elliptical too.


  • Where are the strongest winds found in a hurricane?

  • The strongest winds in a hurricane are found in the eyewall which surrounds the eye. Also, the strongest winds in the eyewall are several thousand feet above the ground above the effects of friction.

  • How big are hurricanes?

  • Hurricanes can very greatly in size. One measurement of hurricanes is how far the tropical storm (gale) force winds (39 mph or greater) extend from the center. Typhoon Tip which occured in the Pacific Ocean in 1979 had tropical storm force winds extend out 675 miles! On the other extreme, Tropical Cyclone Tracy had tropical storm force winds extend out only 30 miles!. On average, hurricanes are 300-400 miles in diameter.

  • How big is the eye of a hurricane?

  • The eye of a hurricane varies greatly in diameter. On average, the eye is about 20 miles wide. The smallest eye ever measured was Hurricane Wilma, also the hurricane with the lowest pressure on record in the Atlantic basin. Wilma's eye had a diameter of just 2 miles. The eye can be very large too. Hurricane eyes can be over 50 miles wide.

  • Do tornadoes form in hurricanes?

  • Tornadoes do form in hurricanes. They are most likely to be found in the right front quadrant of a hurricane relative to storm motion. Tornadoes usually are found in the spiral bands during landfall. The reason for this is that the vertical wind shear increases during landfall which is favorable for tornado formation.

  • How long do hurricanes last?

  • A hurricane ususally lasts several days. It can vary from just one day to in some rare cases last three to four weeks. Any one location can be affected by a hurricane for hours or a couple of days if it happens to stall over a location.

  • What determines the direction that hurricanes move?

  • The direction is determined by the average wind motion over a large area. Hurricanes clouds billow up to the top of the troposphere. Many times wind direction changes with height as well as over the distance of the hurricane. If the wind direction changes with height the hurricane can be sheared or torn into different directions. In this case the low level circulation may continue in one direction where the deep thunderstorm clouds move into another direction.

  • Is it possible to drop a bomb and destroy a hurricane?

  • No chance. The amount of energy that a hurricane contains dwarfs even the largest bombs known.

Hurricane Records and Numbers

  • What was the greatest number of hurricanes to occur at one time?

  • The most hurricanes at one time in the Atlantic was four. It has occured twice, the first time in 1893. The second occurrence was September 25, 1998. The hurricane names were Georges, Ivan, Jeanne and Karl.

  • What is the average number of named storms in the Atlantic each year?

  • The long term average number of named storms in the Atlantic is 9. In a period of higher activity during the years 1995 to 2013, the average was 15 named storms.

  • What is the record number of named storms in the Atlantic?

  • 28 in the year 2005. There was 20 in 1933, and 19 in 1887, 1995, 2010, 2011 , 2012

  • What is the average number of hurricanes in the Atlantic each year?

  • The long term average number of hurricanes in the Atlantic basin is 5 of which 2 become major hurricanes. More recently, since 1995 to 2013, the average number of hurricanes to develop is 8 of which 4 became major hurricanes.

  • What is the average number of hurricanes in the world each year?

  • The long term average number of named storms is 84 globally of which 45 develop in hurricanes (or equivalent tropical cyclone).

  • What was the least number of Atlantic hurricanes on record in one year?

  • There were no hurricanes reported in the years 1907 and 1914.

  • What was the greatest number of Atlantic hurricanes on record in one year?

  • There were 15 hurricanes in the Atlantic basin in the year 2005. 1969 and 2010 were second with 12 hurricanes.

  • What was the greatest number of major Atlantic hurricanes on record in one year?

  • There were 8 in 1950, 7 in 2005, and 6 in the years 1926, 1955, 1961, 1964, 1996, 1999.

  • What was the strongest hurricane on record to hit the U.S.?

  • Strongest U.S. Hurricanes
    Rank Hurricane Name Year Category Pressure
    1 "Keys Labor Day" 1935 5 892 mb
    2 Camille 1969 5 900 mb
    3 Katrina 2005 3 920 mb
    4 Andrew 1992 5 922 mb
    5 Indianola 1886 4 925 mb
    6 FL Keys 1919 4 927 mb
    7 Lake Okeechobee 1928 4 929 mb
    8 Donna 1960 4 930 mb
    8 FL/MS/AL 1926 4 930 mb
    10 Carla 1961 4 931 mb


  • What was the strongest hurricane on record in the Atlantic?
  • The Most Intense Atlantic Hurricanes - The top ten Atlantic hurricanes ranked by pressure
    Rank Hurricane Name Year Category Pressure
    1 Wilma 2005 5 882 mb
    2 Gilbert 1988 5 888 mb
    3 "Keys Labor Day" 1935 5 892 mb
    4 Rita 2005 5 895 mb
    5 Allen 1980 5 899 mb
    6 Camille 1969 5 900 mb
    7 Katrina 2005 5 902 mb
    8 Mitch 1998 5 905 mb
    9 Dean 2007 5 906 mb
    10 Ivan 2004 5 910 mb


  • What was the strongest tropical cyclone on record in the world?

  • The strongest tropical cyclone in the world was Typhoon Tip in 1979. It had a central pressure of 870 mb.

  • What was deadliest hurricane on record to hit the U.S.?

  • The Deadliest U.S. Hurricanes
    Rank Hurricane Name Year Category Deaths
    1 Galveston, TX 1900 4 8000
    2 Lake Okeechobee, FL 1928 4 2500
    3 Katrina 2005 3 1200
    4 Cheniere Caminanda, LA 1893 4 1100-1400
    5 Sea Islands, GA/SC 1893 3 1000-2000
    6 GA/SC 1881 2 700
    7 Audrey 1957 4 416
    8 "Keys Labor Day" 1935 5 408
    9 Last Island, LA 1856 4 400
    10 Miami, FL 1926 4 372


  • What was the costliest hurricane on record to hit the U.S.?

  • Costliest U.S. Hurricanes
    Rank Hurricane Name Year Category Damage
    1 Katrina 2005 3 $108 billion
    2 Ike 2008 2 $29.5 billion
    3 Andrew 1992 5 $26.5 billion
    4 Wilma 2005 3 $21 billion
    5 Ivan 2004 3 $18.8 billion
    6 Charley 2004 4 $15 billion
    7 Rita 2005 3 $12 billion
    8 Frances 2004 2 $9.5 billion
    9 Allison 2001 TS $9 billion
    10 Jeanne 2004 3 $7.7 billion


  • What was the greatest number of hurricanes on record to hit the U.S.?

  • In 1916 and 1985 there were six U.S. landfalling hurricanes. In 1886 data suggests 7 U.S. landfalling hurricanes. Note that data from earlier years may not be totally reliable.

  • What was the fastest pressure drop for a hurricane?
  • The Fastest Pressure Drop in a Hurricane
    Hurricane Name Year 3 Hours 6 Hours 12 Hours 24 Hours
    Felix 2007 50 mb 63 mb
    Wilma 2005 44 mb 54 mb 83 mb 97 mb
    Gilbert 1988 47 mb 72 mb
    Allen 1980 48 mb 56 mb
    Beulah 1967 38 mb


  • What was the heaviest rainfall from a hurricane?

  • The heaviest rainfall from a hurricane was actually Tropical Cyclone Denise. 72 inches of rain fell in 24 hours in a place called Foc-Foc, La Reunion in 1966. The highest ten day total was 223.5 inches in Commerson, La Reunion from Tropical Cyclone Hyacinthe January 1980.

  • What was the highest measured wave from a tropical cyclone?


  • The highest measured wave was 112 feet high! It was measured by the USS Ramapo in the western Pacific February, 1933.

Back to the Tropicalweather.net Home Page. Data on hurricanes courtesy of the National Hurricane Center.