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WMO Publication No. 9 - Weather Reporting
Volume A - Observing Stations




Volume A - Observing Stations
1. Type of Exchange
G: Global
R: Regional
2. Type of Station
3. Index Number
The station index number is composed of the block number (II) and the station number (iii).  The block number defines the area in which the reporting station is situated.  For example: 60360, 60 is the block number for Algeria and 360 is the station number for Annaba.
4. Sub Index Number

A sub-index number is inserted for each station. It is used in the data file to differentiate between two stations with the same index number, usually established at the same (or nearly the same) location/elevation, one for surface and one for upper-air observations. The first station to be established under any station index number always has a sub-index of "0". If a second, separate station with that index number is opened for upper-air observations, it will be assigned a sub-index number of "1".

0 =
First station established under a given station index number (surface and/or upper-air).
1 =
Second station opened under a given station index number, for upper-air observations.
5. Station Name Name of the station.
6. Position
Latitude/Longitude: Latitude/Longitude of the station in degrees, minutes and seconds. The positions of stations north (N) or south (S) of the Equator and east (E) or west (W) of the Greenwich meridian are indicated by the appropriate letters after the seconds figures.
7. Bulletin Identification
The TTAAii CCCC of the abbreviated headings of the meteorological bulletins which contain reports from the station should be inserted.
  8a. Surface Observations
Use the symbol "X" to indicate that the surface observations are made regularly in accordance with a fixed schedule. In cases where the observations fall outside the fixed schedule, the official observation time should be stated. The symbol "-" should be inserted, as appropriate, for non-implementation.
8b. Observation Time Hourly observations (H) - Half hourly observations (S)

This column indicates the hourly and half hourly observations made at the station.  Hourly observations are shown by the letter "H" followed by the period of the day during which they are made.  Similarly, half-hourly observations are shown by the letter "S" followed by the period of the day during which they are made.  Except in a few cases the period begins and ends on the hour, and the times are represented by two figures.  When the period begins or ends at the half-hour the full four-figure time is given.

9.  Elevation HP and H/HA
HP =
Elevation of the station in metres rounded up to two decimals. It is the datum level to which barometric pressure reports at the station refer; such current barometric values being termed "station pressure" and understood to refer to the given level for the purpose of maintaining continuity in the pressure records.
H =
Elevation of the ground in metres (average level of terrain in immediate vicinity of station) rounded up to two decimals is given for stations not located on aerodromes. It is normally also the height of the radiosonde release point.
HA =
Official altitude of the aerodrome given for stations located on aerodromes is indicated by the letter "A" in the column "Other observations and Remarks" of Volume A.

Note: The symbol "#" indicates that the elevation figures are approximate.

10. Upper-air Observations

This column indicates the official observation time fixed by the service for the release of a balloon, parachute or rocket.  Upper-air observations are indicated by means of the use of one or more appropriate letters (see Table 1) below the corresponding standard observation time of 0000 UTC, 0600 UTC, 1200 UTC and 1800 UTC. If the official observation time falls within the period of 45 minutes immediately before the corresponding standard time, the appropriate letters are placed below the standard time. In cases where it does not fall within the standard time, the official observation time should be stated.


Pilot balloon; observation of upper-wind obtained by optical tracking of a free balloon

Radiosonde; observation of atmospheric pressure, temperature and humidity in the upper-air obtained by electronic means.

Radiowind; upper-wind observation obtained by tracking a free balloon by electronic means

The symbol may be used to indicate an upper-air obervation of unspecified type. The symbol "X" is replaced by a time (eg. 23, 02 etc...) when the observation is carried out at a non-standard time

Note: The letters P, R and W are combined as necessary to indicate simultaneous observations (PR or RW)

Table 1

11. Pressure Level
For those stations not indicating pressure reduced to mean sea level (group 4PPPP) in their synoptic reports, the entry in this column shows which information is reported in lieu of group 4PPPP:

Pressure at station level reported using group 3PoPoPoPo
1000 hPa ) Geopotential of the given standard isobaric surface reported using group 4a3hhh
700 hPa   )
500 hPa   )
20. Remarks
Reasons for temporary suspension of observing programmes and an expected date of resumption of the programmes should be given as far as possible. Non-standard collection and/or distribution times should also be included, and also possible alternate observing stations, as appropriate.
Catalogue of Radiosondes and Upper-air Wind Systems

Indicate whether the station is used to generate CLIMAT messages.

C = Station for which monthly climatological means of surface elements are transmitted.
13. GUAN (GCOS) Indicate whether the station is a station of the Global Climate Observing Upper-air Network (GUAN).  Y = Yes; N = No
14. Geo. ht. calc. AUTO/MAN Indicate how the geopotential height calculation will be done: 
AUTO = Automated
MAN = Manual
15. Radiation Correction

Y/N: Indicate if radiation correction is applied or not: Y=Yes  ¦  N = No
Type: If radiation correction is applied indicate the type of identification if known (see Table 2)

Radiation Correction Type
Vaisala RS80 radiation correction 1982
Vaisala RS80 radiation correction 1986
Vaisala RS80 radiation correction 1993
Vaisala RS80 solar correction (86) but no Infra-Red correction
?with  above
Some doubt concerning accuracy

Table 2

16. Ground Equipment Type Type of ground equipment in use at the station
17. Radio Frequency The approximate radiosonde transmitter frequency (MHz) or frequency range regularly used at the station.
18. Radiosonde (see table 3)

Regular: Type of radiosonde regularly used.
Alternative: Alternative type of radiosonde used.

Blank Unknown
AIR Air Intellisonde (USA)
ELIN ELIN (Austria)
IM-MK3 Indian Met. Services Mark 3
J/YANG JINYANG radiosonde (VIZ type)
MARS/MET Meteorit 1 or 2 system (former USSR)
MEIR91/MEIR80 Meisei (Japan)
MES Mesural (French)
MRZ AVK system (Former USSR)
MRZ-T AVK prototype system
MSS Space Data Corp. (USA)
ML-SRS Meteolabor (Switzerland)
SDC Space Data Corp. (USA)
SHANG Shanghai Radio (China)
VRS80* Vaisala RS80 (PTU)
VRS80N* Vaisala RS80 (VLF)
VRS80L* Vaisala RS80 (LORAN)
VRS80G* Vaisala RS80 (GPS)
VRS92-SGP* Vaisala RS92-SGP
? Some doubt on accuracy
* Add in addition to "VRSxx" the letters "H" or "A" depending on the application of the H- or A-Humicap sensors for humidity measurement.


  19. Windfinding
System/Method: Windfinding system or method in use at station.
Equipment: Windfinding equipment in use at station.
  20. Remarks Any other information pertaining to the station.



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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