International Best Track Archive for Climate Stewardship Project

Storm Identifier

Year in which the storm occurred

The cardinal number of the system for that season. The count includes all basins, so this will not be continuous for basin files.

Basins include:

• NA: North Atlantic
• EP: Eastern North Pacific
• WP: Western North Pacific
• NI: North Indian
• SI: South Indian
• SP: Southern Pacific
• SA: South Atlantic
• MM: Missing - should not appear in final IBTrACS product

Subbasins include:

• MM: missing - no sub basin for this basin (no subbasins provided for WP, SI)
• CS: Caribbean Sea
• GM: Gulf of Mexico
• CP: Central Pacific
• BB: Bay of Bengal
• AS: Arabian Sea
• WA: Western Australia
• EA: Eastern Australia

Name provided by the agency

ISO Time provided in Universal Time Coordinates (UTC). Format is YYYY-MM-DD HH:mm:ss Most points are provided at 6 hour intervals. Some agencies provided 3 hour points (e.g., New Delhi) or times at important observations (e.g.,landfall times in the North Atlantic,etc)

Combined storm type. This is assigned based on all available storm types. Values:

• DS: Disturbance
• TS: Tropical
• ET: Extratropical
• SS: Subtropical
• NR: Not reported
• MX: Mixture (contradicting nature reports from different agencies)

Maximum sustained wind speed from the WMO agency for the current location. NO adjustment is made for differences in wind speed averaging periods. hurdat/atcf = North Atlantic - U.S. Miami (NOAA NHC) - 1-minute winds tokyo = RSMC Tokyo (JMA) - 10-minute newdelhi = RSMC New Delhi (IMD) - 3-minute reunion = RSMC La Reunion (MFLR) - 10 minute bom = Australian TCWCs (TCWC Perth, Darwin, Brisbane) - 10-minute nadi = RSMC Nadi (FMS) - 10 minute wellington = TCWC Wellington (NZMS) - 10-minute

Minimum central pressure assigned by the responsible WMO agnecy

This is the reporting agency responsible for the basin as currently listed.It should be noted that many of the agencies did not accept official WMO responsibility until relatively recently, e.g., La Reunion in 1993 or IMD in 1990. Therefore the WMO agency is used loosely to describe the currently responsible agency.

Track type Tropical storms can interact. Values:

• PROVISIONAL: Real time data used to populate the position and other parameters of this system.This is a provisional track that will be replaced when reanalysis of the storm is performed. (Usually within 2 years of the storm's occurence)
• PROVISIONAL_spur: Real time data (see provisional description above) but due to differences in positions between various inputs, algorithm can not identify accurate position. When counting storms, these should not likely be counted. These should be rare for PROVISIONAL data.
• MAIN: primary track associated with a storm system. This is a track that has had some reanalysis and is higher quality than provisional data.
• spur: usually short lived tracks associated with a main track and often represents alternate positions at the beginning of a system. Can also represent actual system interactions (e.g., Fujiwhara interactions).

Distance to land from the current position. The land dataset includes all continents and any islands larger than 1400 km^2. The distance is the nearest at the present time in any direction.

Nearest location to land within next 6 hours. This can be thought of a landfall flag: =0 -- Landfall within 6 hours.

0 -- No landfall within next 6 hours. Calculations are based on storm center (columns 9,10). Values less than 60 nmile likely are impacted by the system even though the center of the system is not over land. The uses the same land mask as DIST2LAND.

Interpolation Flag A 14 character flag string which denotes the source of each agency's report. Values:

• _: missing reports. No information provided.
• O: original report as provided by the agency.
• P: position was interpolated (all variables were interpolated/filled, including intensity)
• I: Position was provided, but Intensity variables (and likely other variables) were interpolated/filled
• V: Position and intensity variables are original but some variables were interpolated/filled.

The order of the 14 characters refers to the following 14 datasets:

• 1: USA Agency (see column 18)
• 2: Tokyo
• 3: CMA
• 4: HKO
• 5: NewDelhi
• 6: Reunion
• 7: BoM
• 8: Nadi
• 9: Wellington
• 10: ds824
• 11: TD9636
• 12: TD9635
• 13: Neumann Southern Hemisphere data set
• 14: M.L. Chenoweth N Atlantic Historic dataset

The agency file providing the information: The representative US agency data is derived from a hierarchical selection: the first dataset in the following list to provide information at the given time is used as the USA_agency. Values:

• HURDAT_ATL
• HURSAT_EPA
• ATCF (for NA and EP basins only)
• JTWC_WP
• JTWC_IO
• JTWC_EP
• JTWC_CP
• JTWC_SH
• CPHC [separate file provided by CPHC for years 1966-2003, 2008]
• tcvitals - THIS INDICATES THAT THE DATA ARE PRELIMINARY

While these agencies are generally orthogonal, there are cases where a system is provided in more than one source. In this case, the report from the highest source is used. ATCF format info from: https://www.nrlmry.navy.mil/atcf_web/docs/database/new/abdeck.txt HURDAT2 info from: http://www.nhc.noaa.gov/data/hurdat/hurdat2-format-atlantic.pdf

The ATCF ID is assigned by US agencies and can be used to comparethe storm with other US cyclone-related datasets. If two (or more) ATCF tracks make up one storm, then the IDs are separated by a colon. The format of the ATCF ID is B where bb is the basin ID, nn is the number of the storm in that basin and yyyy is the year. Possible basin values are:

• AL: North Atlantic
• SL: South Atlantic
• EP: East Pacific
• WP: West Pacific
• SH: Southern Hemisphere
• IO: North Indian

For the provisional data, other basin identifiers were provided that include:

• CP: Central Pacific
• SP: South Pacific
• SI: South Indian
• AS: Arabian Sea (North Indian)
• BB: Bay of Bengal (North Indian)

USA Latitude

USA Longitude

Record identifier. Values:

• C: Closest approach to a coast, not followed by a landfall
• G: Genesis
• I: An intensity peak in terms of both pressure and wind
• L: Landfall (center of system crossing a coastline)
• P: Minimum in central pressure
• R: Provides additional detail on the intensity of the cyclone when rapid changes are underway
• S: Change of status of the system
• T: Provides additional detail on the track (position) of the cyclone
• W: Maximum sustained wind speed

Status of system. Values:

• DB: disturbance
• TD: tropical depression
• TS: tropical storm
• TY: typhoon
• ST: super typhoon
• TC: tropical cyclone
• HU,HR: hurricane
• SD: subtropical depression
• SS: subtropical storm
• EX: extratropical systems
• PT: post tropical
• IN: inland
• DS: dissipating
• LO: low
• WV: tropical wave
• ET: extrapolated
• MD: monsoon depression
• XX: unknown

Maximum sustained wind speed in knots: 0 - 300 kts

Minimum sea level pressure, 850 - 1050 mb.

Saffir-Simpson Hurricane Scale information based on the wind speed provided by the US agency wind speed (US agencies provide 1-minute wind speeds) Values:

• -5: Unknown [XX]
• -4: Post-tropical [EX, ET, PT]
• -3: Miscellaneous disturbances [WV, LO, DB, DS, IN, MD]
• -2: Subtropical [SS, SD]

Tropical systems classified based on wind speeds [TD, TS, HU, TY,, TC, ST, HR] Values:

• -1: Tropical depression (W<34)
• 0: Tropical storm [34<W<64]
• 1: Category 1 [64<=W<83]
• 2: Category 2 [83<=W<96]
• 3: Category 3 [96<=W<113]
• 4: Category 4 [113<=W<137]
• 5: Category 5 [W >= 137]

34 kt wind radii maximum extent in northeastern quadrant

34 kt wind radii maximum extent in southeastern quadrant

34 kt wind radii maximum extent in southwestern quadrant

34 kt wind radii maximum extent in northwestern quadrant

50 kt wind radii maximum extent in northeastern quadrant

50 kt wind radii maximum extent in southeastern quadrant

50 kt wind radii maximum extent in southwestern quadrant

50 kt wind radii maximum extent in northwestern quadrant

64 kt wind radii maximum extent in northeastern quadrant

64 kt wind radii maximum extent in southeastern quadrant

64 kt wind radii maximum extent in southwestern quadrant

64 kt wind radii maximum extent in northwestern quadrant

pressure in millibars of the last closed isobar, 900 - 1050 mb NOT BEST-TRACKED (not reanalyzed)

radius of the last closed isobar, 0 - 999 n mi. NOT BEST TRACKED (not reanalyzed)

radius of max winds, 0 - 999 n mi. NOT BEST TRACKED (not reanalyzed)

eye diameter, 0 - 120 n mi. NOT BEST TRACKED (not reanalyzed)

Tokyo Latitude

Tokyo Longitude

Grade Values:

• 1: Not used
• 2: Tropical Depression (TD)
• 3: Tropical Storm (TS)
• 4: Severe Tropical Storm (STS)
• 5: Typhoon (TY)
• 6: Extratropical Cyclone (L)
• 7: Just entering into the responsible area of Japan Meteorological Agency (JMA)
• 8: Not used
• 9 : Tropical Cyclone of TS intensity or higher

Maximum sustained wind speed [10-min averaging period]

Central pressure

• 1: Northeast (NE)
• 2: East (E)
• 3: Southeast (SE)
• 4: South (S)
• 5: Southwest (SW)
• 6: West (W)
• 7: Northwest (NW)
• 8: North (N)
• 9: (symmetric circle)

The longest radius of 50kt winds or greater

The shortest radius of 50kt winds or greater

• 1: Northeast (NE)
• 2: East (E)
• 3: Southeast (SE)
• 4: South (S)
• 5: Southwest (SW)
• 6: West (W)
• 7: Northwest (NW)
• 8: North (N)
• 9: (symmetric circle)

The longest radius of 30kt winds or greater

The shortest radius of 30kt winds or greater

Landfall or passage over the Japanese islands occurred within one hour after the time of the analysis with this indicator.

CMA Latitude

CMA Longitude

Intensity category according to the Chinese National Standard for Grade of Tropical Cyclones (which has been used since 15 June 2006). Values:

• 0: Weaker than Tropical Depression or unknown intensity
• 1: Tropical Depression (TD: 10.8-17.1 m/s)
• 2: Tropical Storm (TS:17.2-24.4 m/s)
• 3: Severe Tropical Storm (STS: 24.5-32.6 m/s)
• 4: Typhoon (TY: 32.7-41.4 m/s)
• 5: Severe Typhoon (STY: 41.5-50.9 m/s)
• 6: Super Typhoon (SuperTY: ≥51.0 m/s)
• 9: Extratropical Cyclone (ET) stage

Two-minute mean maximum sustained wind (MSW; m/s) near the TC center. WND = 9 indicates MSW < 10 m/s, WND = 0 indicates unknown intensity.

HKO Latitude

USA Longitude

After 2009, we further classified two more storm types above typhoon, so there are in total 7 storm types LW (Low) <22 kt TD (Tropical Depression) 22 - 33 kt TS (Tropical Storm) 34 - 47 kt STS (Severe Tropical Storm) 48 - 63 kt T (Typhoon) 64 - 80 kt ST (Severe Typhoon) 81 - 99 kt SuperT (Super Typhoon) >= 100 kt

Maximum sustained wind speed

Minimum sea level pressure

NewDelhi Latitude

NewDelhi Longitude

Types of disturbances:

• Low pressure area: W<17 knots
• D: Depression 17<=W<28
• DD: Deep Depression 28<=W<34
• CS: Cyclonic Storm 34<=W<48
• SCS: Severe Cyclonic Storm 48<=W<64
• VSCS: Very Severe Cyclonic Storm 64<=W<120
• SCS: Super Cyclonic Storm W>=120 knots

Maximum sustained wind speed

Minimum sea level pressure

Dvorak CI-number

New Delhi DP

Environmental pressure in which the cyclone is embedded

Reunion Latitude

Reunion Longitude

• 01: tropics; disturbance ( no closed isobars)
• 02: <34 knot winds, <17m/s winds and at least one closed isobar
• 03: 34-63 knots, 17-32m/s
• 04: >63 knots, >32m/s
• 05: extratropical
• 06: dissipating
• 07: subtropical cyclone (nonfrontal, low pressure system that comprises initially baroclinic circulation developing over subtropical water)
• 08: overland
• 09: unknown

Maximum average wind speed

Central pressure

Dvorak T-number

Dvorak CI-number

Radius of maximum winds

34 kt wind radii maximum extent in northeastern quadrant

34 kt wind radii maximum extent in southeastern quadrant

34 kt wind radii maximum extent in southwestern quadrant

34 kt wind radii maximum extent in northwestern quadrant

50 kt wind radii maximum extent in northeastern quadrant

50 kt wind radii maximum extent in southeastern quadrant

50 kt wind radii maximum extent in southwestern quadrant

50 kt wind radii maximum extent in northwestern quadrant

64 kt wind radii maximum extent in northeastern quadrant

64 kt wind radii maximum extent in southeastern quadrant

64 kt wind radii maximum extent in southwestern quadrant

64 kt wind radii maximum extent in northwestern quadrant

BOM Latitude

BOM Longitude

This indicates the type of system that this cyclone was at the time of the observation. Note that cyclones can evolve during their lifetimes and hence change type mid-stream (e.g. Extratropical transition (ETT))

This is the estimated maximum mean wind around the cyclone - that is in the vicinity of the centre

Central pressure of the cyclone

Dvorak T-number

Dvorak CI-number

This is the mean radius (from the system centre) of the maximum mean wind

This is the mean radius (from the system centre) of the extent of winds; gale-force (17m/s) or above. The four sectors show the mean extent in the respective quadrant centred on the cardinal point. Northeast quadrant

This is the mean radius (from the system centre) of the extent of winds; gale-force (17m/s) or above. The four sectors show the mean extent in the respective quadrant centred on the cardinal point. Southeast quadrant

This is the mean radius (from the system centre) of the extent of winds; gale-force (17m/s) or above. The four sectors show the mean extent in the respective quadrant centred on the cardinal point. Southwest quadrant

This is the mean radius (from the system centre) of the extent of winds; gale-force (17m/s) or above. The four sectors show the mean extent in the respective quadrant centred on the cardinal point. Northwest quadrant

This is the mean radius (from the system centre) of the extent of winds; gale-force (25m/s) or above. The four sectors show the mean extent in the respective quadrant centred on the cardinal point. Northeast quadrant

This is the mean radius (from the system centre) of the extent of winds; gale-force (25m/s) or above. The four sectors show the mean extent in the respective quadrant centred on the cardinal point. Southeast quadrant

This is the mean radius (from the system centre) of the extent of winds; gale-force (25m/s) or above. The four sectors show the mean extent in the respective quadrant centred on the cardinal point. Southwest quadrant

This is the mean radius (from the system centre) of the extent of winds; gale-force (25m/s) or above. The four sectors show the mean extent in the respective quadrant centred on the cardinal point. Northwest quadrant

This is the mean radius (from the system centre) of the extent of winds; gale-force (33m/s) or above. The four sectors show the mean extent in the respective quadrant centred on the cardinal point. Northeast quadrant

This is the mean radius (from the system centre) of the extent of winds; gale-force (33m/s) or above. The four sectors show the mean extent in the respective quadrant centred on the cardinal point. Southeast quadrant

This is the mean radius (from the system centre) of the extent of winds; gale-force (33m/s) or above. The four sectors show the mean extent in the respective quadrant centred on the cardinal point. Southwest quadrant

This is the mean radius (from the system centre) of the extent of winds; gale-force (33m/s) or above. The four sectors show the mean extent in the respective quadrant centred on the cardinal point. Northwest quadrant

The estimated mean radius of the outermost closed isobar (1-hPa spacing).

Environmental pressure in which the cyclone is embedded

Mean radius of the cyclone eye.

This indicates the tools that were used to derive the centre location of the system. Values:

• NULL: Default - unknown
• 1: no sat, no rad, no obs
• 2: no sat, no rad, obs only
• 3: Sat IR/Vis; no clear eye
• 4: Sat IR/Vis; clearly defined eye
• 5: aircraft radar report
• 6: land-based radar report
• 7: Sat IR/Vis & rad & obs
• 8: report inside eye
• 10: Sat- Scatterometer
• 11: Sat- Microwave
• 12: Manned Aircraft Reconnaissance
• 13: UAV Aircraft Reconnaissance

This code may need to be expanded to handle new systems in the future, and also to differentiate between pressure-wind relationships used to derive the central pressure.

Cyclone latitude from RSMC Nadi, Fiji

Cyclone longitude from RSMC Nadi, Fiji

Nadi assigned category

Cyclone latitude from TCWC Wellington

Cyclone longitude from TCWC Wellington

Wellington assigned wind speed

Wellington assigned central pressure

Cyclone latitude from dataset 824

Cyclone longitude from dataset 824

TC - Tropical cyclone

Maximum wind speed

Central pressure

Cyclone latitude from NCEI dataset TD9636

Cyclone longitude from NCEI dataset TD9636

This field gives an estimate of the highest winds occurring in the storm at the time and location indicated. The entire storm was coded as to the highest stage reached for some of the earlier years. Values:

• 0: Tropical disturbance (1969 onward)
• 1: depression < 34 [some variation in definition for S Indian]
• 2: Storm 34-63 [with some variation in definition for S Indian]
• 3: point where wind reached 64 knots [except N Indian where it is wind 43-47 knots]
• 4: Hurricane > 64 [except in N Indian, Wind > 48]
• 5: Extratropical
• 6: Dissipating
• 7: Unknown Intensity or doubtful track

Estimated highest wind speed at the time indicated. These estimates are subjective and must be interpreted with caution.

Minimum sea level pressure

Size. (Radius of system)

Cyclone latitude from C. Neumann Souther Hemisphere dataset

Cyclone longitude from C. Neumann Souther Hemisphere dataset

• EX: Extratropical
• TC: Tropical
• MM: Missing

Maximum wind speed

Central pressure

Cyclone latitude from M. Chenoweth dataset

Cyclone longitude from M. Chenoweth dataset

Storm classification Values:

• EX: Extratropical
• HU: Hurricane
• LO: Low
• MH:
• SD: Subtropical depression
• SS: Subtropical storm
• TD: Tropical Depression
• TS: Tropical Storm
• TW:
• WV: Open Wave

Maximum wind speed

Central pressure

Gust reportd by the USA_AGENCY.

This is the estimated maximum wind gust around the cyclone - that is in the vicinity of the centre based on open terrain estimate

This is the period of the gust used when measuring max wind gusts. This parameter will only be used when receiving data in WMO format that is not based on 3-sec gusts. All Australian based data should be based on 3-sec gusts.

Maximum Wind Gust

Gust Period

Wave height for radii defined in SEARAD

Radial extent of seas (as defined in SEAHGT) extending from storm center to the Northeast.

Radial extent of seas (as defined in SEAHGT) extending from storm center to the Southeast.

Radial extent of seas (as defined in SEAHGT) extending from storm center to the Southwest.

Radial extent of seas (as defined in SEAHGT) extending from storm center to the Northwest.

Translation speed of the system as calculated from the positions in LAT and LON

Translation direction of the system as calculated from the positions in LAT and LON. Direction is moving toward the vector pointing in degrees east of north [range = 0-360 deg]