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Tropical Cyclone Database Updated Twice Weekly

IBTrACS contains detailed information on every storm worldwide

Satellite image of Hurricane Dorian from Sept 2019
Courtesy of NOAA NESDIS

NCEI’s global inventory of tropical cyclones has become even more useful. 

The International Best Track Archive for Climate Stewardship (IBTrACS), created and maintained by NCEI scientists in collaboration with weather agencies around the world, is designed to make the most reliable historical information about tropical cyclones readily available to forecasters, government agencies, and the private sector. 

IBTrACS is useful to anyone interested in knowing the tracks tropical cyclones have followed, the strength of their winds, how quickly they have grown in intensity, and how storm patterns are changing. 

IBTrACS version 4 provides near-real-time data for the first time, allowing users to analyze current storms in the context of historical data.

A Global Storm Archive

“Tropical cyclone” is the term for low-pressure storm systems that form over warm water at low latitudes on either side of the equator. In the Atlantic and Eastern Pacific oceans, cyclones with wind speeds of at least 74 miles per hour are called hurricanes, whereas such storms are known as typhoons in the Northwest Pacific.

Regardless of regional nomenclature, IBTrACS archives the most accurate data for every tropical cyclone worldwide. After each storm has ended, IBTrACS gathers information from a wide range of authoritative sources, including all of the Regional Specialized Meteorological Centers. Scientists evaluate and merge this information to provide a central location for every storm’s track and then add the information to the database. The data date back to 1842, though coverage is sparse until 1945. 

First made available in late 2008, IBTrACS now has more than 1,000 registered users. Climate scientists use IBTrACS to study changes in the distribution, frequency, and intensity of cyclones over time. Other users include the Federal Emergency Management Agency (FEMA), local community planners, media organizations, oil companies planning offshore exploration, and economists studying the impacts of storms. The reinsurance industry uses IBTrACS to understand the storm risks of their clients. 

Data in Near-Real Time 

To further NCEI’s goals of openness and easy access, IBTrACS data-processing methods are transparent, with data sources fully recorded and all observations and corrections clearly tracked. Users are encouraged to offer feedback, which is used to improve the database.

Significant changes in version 4 include:

  • Near-real-time data: Many users request information on recent storms for use in comparisons with historic storms. The previous version was updated annually in September, which meant that the time lag between a storm and its inclusion in the database could be as long as 18 months. The new version is updated twice a week, with data from more sources. IBTrACS collects and assimilates the working versions of best tracks as “provisional data,” meaning that the initial data on position, intensity, and other factors may change after further analysis and validation by NCEI and database users.

  • Fewer formats: To simplify support, data are available in only the three most-requested formats—netCDF, CSV, and shapefile—with each format containing precisely the same information. Although the change represents a reduction in the number of available formats, it increases uniformity, supports ease of use, and allows for improved customer service.

The many users of IBTrACS should find the new version even more valuable than before—and if they see aspects that could be improved, NCEI encourages feedback.