 NCDC / Climate Monitoring / Hurricanes / Help
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This section contains links to NCDC and NOAA pages summarizing the current and recent hurricane seasons, indices of hurricane and typhoon activity and also a link to a list of all U.S.-landfalling Atlantic hurricanes since 1851.
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Intro to hurricanes|
This section contains information and background about hurricanes and hurricane climatology, especially in the Atlantic |
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Tropical cyclones are known by different names in different parts of the world - hurricanes in the Atlantic and eastern Pacific, typhoons in the western Pacific and cyclones in the Indian Ocean. However, they all form and behave in similar ways, with the only substantial difference being the direction of rotation between the northern and southern hemispheres. In the Northern Hemisphere, hurricanes rotate counter-clockwise and vice versa for the Southern Hemisphere. The Saffir-Simpson scale (shown in the table below) is the measure of a hurricane's intensity and defines tropical systems with windspeeds of 39 mph (a minimal tropical storm) to over 155 mph (a major category 5 hurricane). These categories help to forecast potential damage associated with a landfalling tropical cyclone. |
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Generally speaking, a minimal tropical storm will cause only light damage and will pick up only light unsecured items. There is seldom significant damage to buildings. A category one hurricane can cause damage to trees and bushes and unsecured mobile homes. Usually, stable structures are not significantly affected. A storm surge of 4-5 ft can be expected with a category one storm and some coastal road flooding is possible. On the other extreme, a category five storm (such as Andrew in 1992, or Mitch in 1998) will destroy all mobile homes and blow down all trees and shrubs. Many substantial, secure buildings will have total roof failure and extensive window and door damage. Storm surge can be anticipated at around 18 ft with a category five storm. |
| Hurricane Season in the Atlantic runs from 1 June to 30 November, however hurricanes can and do occasionally form outside this season as well. The most active month, statistically is September in the Atlantic. For the eastern Pacific, the season is a little longer beginning in late May and running until late October/early November, with a peak also in late August/early September. |
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As can be seen in the graph to the right, Atlantic hurricane activity appears to have phases. Since around 1995 the Atlantic has been more active than the long-term mean. However, within these multidecadal phases, certain years will be influenced by factors such as El Ni�o or La Ni�a. Typically for the Atlantic this translates to fewer hurricanes in El Ni�o years and more in La Ni�a years. |
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Useful Links
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Questions?| For all climate questions other than questions concerning this report, please contact the National Climatic Data Center's Climate Services Division: |
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Climate Services Division NOAA/National Climatic Data Center 151 Patton Avenue Asheville, NC 28801-5001 fax: 828-271-4876 phone: 828-271-4800 email: questions@ncdc.noaa.gov |
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For further information on the historical climate perspective presented in this report, contact: |
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David Levinson NOAA/National Climatic Data Center 151 Patton Avenue Asheville, NC 28801-5001 fax: 828-271-4328 email: David.Levinson@noaa.gov |
NCDC / Climate Monitoring / Climate of 2004 / hurricanes / Search / Help
http://www.ncdc.noaa.gov/oa/climate/research/hurricanes.html