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Part 1 - Observational Data AND Part 2 - Grid and Grib Bulletins
Semi annual updates: File Naming Record Format File Transfer
Advanced Notifications: File Naming Record Format File Transfer

No Field Name Type Width Description
1 Sequence No. Numeric 4 Sequence number of record according to the increment manner through the year. There are two different series of the sequence numbers (0001 to 9999) for "observational data" and one for "products” which are initialized at the beginning of each year.
2 ChangeType Character 2 Type of change to the record whose contents are shown in the last twelve fields (field No.4 to 15).
  • DD = deleting a record (ie deleting a bulletin)
  • AA = adding a record (ie adding a new bulletin)
  • DM = deletion of the record for modification
  • AM = addition of the record for modification
Explanation: When modifying an entry use “DM” for deletion of an existing record to be modified and “AM” for addition of the modified record.  The placement order of the records in the file is important.  The record to be modified with the type of “DM” should be followed by the modified one with the type of “AM”.  It shows that the “DM” record is replaced by the “AM” one.

3 ChangeDate Character 10 Date from which this change becomes effective, in the form of day/month/year (e.g. 01/01/2008 for 1st January 2008).
4 Region Numeric 1
WMO Regions:
1 Region I 4 Region IV 7 Antarctic
2 Region II 5 Region V    
3 Region III 6 Region VI    
5 RTH Character Variable Regional Telecommunication Hub whose zone of responsibility corresponds to the bulletin.
6 Country Character Variable Country where centre is located.
7 Centre Character Variable Centre (usually the NMC) who originates the bulletin or controls the originator of the bulletin.
8 Date Character 10 Date when record becomes effective. day/month/year (e.g. 05/12/2008 for 5th December 2008).
9 Category Character 1
  • A= Additional data/products
  • E= Essential data/products
  • O= Other data/products
10 TTAAii Character 6 Abbreviated heading of the bulletin (a):
  • TT = standard data designators (b)
  • AA = Geographical designator (b)

    (a) See WMO Publication 386: Manual on the GTS, Att. II-5, Vol I, Pt II, para 2.3.2 for full details of abbreviated headings.
    (b) See Attachment II-5 of the above-mentioned publication WMO No. 386 for WMO standard data designators ("TT....") and geographical designators ("..AA..").
11 CCCC Character 4 International four-letter location indicator, used in the abbreviated heading (see Annex I)
12 CodeForm Character Variable FM code form - see WMO No 306 – Manual on Codes eg: FM 51 – XII; PLAIN LANGUAGE.
13 TimeGroup Character Variable Time(s) in UTC (= "GG"): For bulletins containing meteorological reports: The standard time of observation, in UTC;

For aerodrome, route and area (aeronautical) forecasts: The hour (in UTC) during which the transmission is made (eg 15 is shown if the transmission time is 15:30)

For other forecasts and analyses: The standard time, in UTC, of the observation on which the forecast or analysis is based.

For other messages:
The time of issuing, in UTC as GG in YYGGgg group of the abbreviated heading. Day of month for the bulletin issued on a fixed day every month.

Other comment on issuance of a bulletin could be inserted in “Remarks” field.
14 Content Character Variable Contents of the bulletin: the international station index number or the international four-letter indicator (ICAO location indicators) of stations whose reports are included in the bulletin. For GRID and GRIB bulletins, area of coverage and grid spacing.
15 Remarks Character Variable Memo field used for any information not described in the preceding fields. In case that contents of a GRID/GRIB bulletin differ from those derived from the abbreviated heading, such information as parameters on actual contents should be inserted in this field.


CBS Meetings
Reports of Meetings
WWW OIS Newsletter
Current News
Newsletter Archive
Observing Stations
WMO No 9 - Volume A
Radiosonde Catalogue
Bulletins TTAAii CCCC
WMO No 9 - Volume C1
Routeing Catalogues
Additional Data/Product
Bulletin Comparisons
T1T2A1A2ii Data Designators
Transmission Programmes
WMO No 9 - Volume C2
WMO No9 - Volume D
WMO No 47
Data Buoys
Data Quantity
Data Quality

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