HURDAT

The North Atlantic hurricane database, or HURDAT, is the database for all tropical cyclones in the Atlantic Ocean, Gulf of Mexico and Caribbean Sea, since 1851.^[1][2][3] It is also a database of all Pacific hurricanes.^[4][5]

History

The original database of six-hourly positions and intensities were put together in the 1960s in support of the Apollo space program to help provide statistical track forecast guidance. In the intervening years, this database – which is now freely and easily accessible on the Internet from the National Hurricane Center's (NHC's) Webpage – has been utilized for a wide variety of uses: climatic change studies, seasonal forecasting, risk assessment for county emergency managers, analysis of potential losses for insurance and business interests, intensity forecasting techniques and verification of official and various model predictions of track and intensity.

HURDAT was not designed with all of these uses in mind when it was first put together and not all of them may be appropriate given its original motivation. HURDAT contains numerous systematic as well as some random errors in the database. Additionally, analysis techniques have changed over the years at NHC as their understanding of tropical cyclones has developed, leading to biases in the historical database. Another difficulty in applying the hurricane database to studies concerned with landfalling events is the lack exact location, time and intensity at hurricane landfall.

How to read

Example — Tropical Depression 14 (1987)

11530 TD — Strength on SSHS

11540 :10/31/1987 :M= 5 7 :SNBR= 184  :XING=0 - Card number, Date of formation, the number of days the storm was above Tropical Disturbance strength for.

0000UTC 0600UTC 1200UTC 1800UTC

Card No :Date :LONG(N) :LAT(W) Wind

11550  :10/31* 0 0 0 0*0 0 0 0*0 0 0 0*165 775 30 0*

11560  :11/1* 175 785 30 0*184 793 30 0*195 799 30 0*201 803 30 0*

11570  :11/2* 203 805 25 0*207 808 25 0*211 811 25 0*214 814 25 0*

11580  :11/3* 223 818 25 0*232 822 25 0*240 829 25 0*249 836 25 0*

11590  :11/4* 257 839 25 0*267 835 25 0*275 830 20 0*285 820 20 0*

11600 TD

• Key
• Long = Longitude in tenths of a degree west
• Lat= Latitude in tenths of a degree north
• Wind= Wind speed in Knots

The Atlantic hurricane database

The initial requirement for computerized tropical cyclone data at the National Hurricane Centre, came during the mid 1960s after NASA's Apollo space programme needed data on the climatological impact of tropical cyclones on launches of space vehicles at the Kennedy Space Center.^[6] The basic data was taken by John Hope and Charles Neumman from the National Weather Records North Atlantic Tropical Cyclone deck number 988 who updated it to include data from 1886 - 1968 and applied several corrections to the data.^[7]

In 2013, the archives format was significantly changed to include non-synoptic best track times, non-developing tropical depressions and wind radii.^[8]

The Eastern and Central Pacific hurricane database

The Eastern Pacific best track database was initially compiled on magnetic tape in 1976 for the seasons between 1949 and 1975, at the NHC to help with the development of two tropical cyclone forecast models, which required tracks of past cyclones as a base for its predictions.^[9][10] The database was based on records held by the United States Navy and were interpolated from 12 hourly intervals to 6 hourly intervals based on a scheme devised by Hiroshi Akima in 1970.^[11][12] Initially tracks for the Central Pacific region and tracks for tropical depressions that did not develop into tropical storms or hurricanes were not included within the database.^[12] After the database had been created Arthur Pike of the NHC made some internal adjustments, while in 1980 a review was made by Arnold Court under contract from the United States National Weather Service and resulted in additions and/or modifications to 81 tracks in the database.^[11][13] Between 1976 - 1987, the NHC archived best track data from the Eastern Pacific Hurricane Center (EPHC), and in 1982 started including information on Central Pacific tropical storms and hurricanes started to be included in the database based on data from the Joint Typhoon Warning Center and research done by Samuel Shaw of the Central Pacific Hurricane Center (CPHC) in 1981.^[9][11] The format of the database was completely revised by the NHC during 1984, so that the format could resemble the Atlantic database before they took over the warning responsibility from the EPHC for the Eastern Pacific during 1988.^[11][13][14] In 2013, the archives format was significantly changed to include non-synoptic best track times, non-developing tropical depressions and wind radii.^[5]

Reanalysis projects

Both the Atlantic and Eastern Pacific HURDAT Databases are in the process of being re-analysed by the NHC, as they contain several random and systematic errors that have become apparent as analysis techniques have developed over the years. For the Atlantic HURDAT efforts to re-analyse the whole of the period between 1851 to the end of the 20th Century got under way in 2001 when data for the years 1851 to 1856 were added to the database. These additions and changes were based on the groundbreaking work of the late Jose Fernandez-Partagas, who uncovered numerous, previously undocumented, hurricanes from the late 19th and early 20th centuries. The second time the database was updated was August 2002 when Hurricane Andrew was upgraded to a Category 5 hurricane. In addition to these changes additional analyses, digitization and quality control of the data was carried out by researchers at the NOAA Hurricane Research Division funded by the NOAA Office of Global Programs. By 2010, re-analysis had been completed as far as the 1930 Atlantic season. Official changes to the Atlantic hurricane database are approved by the National Hurricane Center Best Track Change Committee. Thus research conducted by Chris Landsea and colleagues as part of the Atlantic hurricane database reanalysis project likewise goes through this review process. Not all Landsea's recommendations are accepted by the Committee.

References