|Frequently Asked Questions
related to Tropical Weather
The hurricane season in the Atlantic Basin, which includes the North Atlantic Ocean, Caribbean Sea and Gulf of Mexico, runs from June 1 to November 30 each year. In the eastern Pacific, the season begins on May 15 and ends November 30. Of course, hurricanes and tropical storms can and do form outside these time periods, albeit rarely. In 2003, Ana was the frist tropical storm of record to develop during the month of April. Odette and Peter both developed in December of that same year, after the official end of the hurricane season. This marked the first time since 1887 that two tropical storms formed in the month of December. These three storms made the 2003 hurricane season one of the longest in the Atlantic Basin since records began.
Atlantic tropical systems are named from lists maintained and updated by an international committee of the World Meteorological Organization. Six lists are used in rotation. Thus, the 1999 list of names will be used again in 2005. At the beginning of each season, the first storm is always the A storm no matter how many storms formed in the previous season. A seperate set of six name lists is used for Eastern Pacific storms. For storms that form elsewhere in the Pacific Ocean, around Australia and Papua New Guuinea, or in the Indian Ocean, names are used sequentially. In other words, if the last storm of the 1999 season was the M storm, the first storm of the 2000 season will have a name beginning with N. When the bottom of one list is reached, the next name is taken from the top of the next list.The only time that the name lists are changed is if a storm is so deadly or costly that the future use of its name on a different storm would be inappropriate for reasons of sensitivity. To see the various name lists for the world's tropical systems and to learn more about the retirement of hurricane names, please see the National Hurricane Center's page on the topic at http://www.nhc.noaa.gov/aboutnames.shtml.
When a tropical system first begins to organize, it is initially called a tropical depression. Once sustained wind speeds reach 39 mph, the system is upgraded to a tropical storm and given a name. If a tropical storm intensifies to the point where sustained winds reach 74 mph or greater, it is classified as a hurricane. The strength of a hurricane is categorized by the Saffir-Simpson scale. There are five categories on the scale which are used to estimate the storms potential for property damage and flooding were it to make landfall. Details about the Saffir-Simpson scale can be found at http://www.nhc.noaa.gov/aboutsshs.html.
Descriptions of the various models that are used by the National Hurricane Center to make official intensity and track forecasts can be found here.
NOAA & FEMA maintain a Hurricane Awareness Web Site with plenty of useful information to help you make informed decisions about preparing your property and family for the potential impacts of a tropical storm or hurricane. Another version of the website is available en Español. This website is updated and highlighted each year before the beginning of Hurricane Season during Hurricane Preparedness Week. In 2004, Hurricane Preparedness Week ran from May 16-22.
Answers to an abundant collection of Frequently Asked Questions are available on the National Hurricane Center's web site.