| 1. |
Type of Exchange |
|
| 2. |
Type of Station |
| S: |
SYNOP |
| T: |
TEMP |
| P: |
PILOT |
|
| 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,separatestation 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 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. |
|
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. |
|
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.
|
| 8. |
Elevation or Altitude:
HP, H or HA |
| HP= |
Elevation¹ 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= |
For stations not located on aerodromes: elevation¹ of the ground (height above mean sea level of the ground on which the raingauge stands or, if there is no raingauge, the ground beneath the thermometer screen. If there is neither raingauge nor screen, it is the average level of terrain in immediate vicinity of station) in metres rounded up to two decimals. |
| HA= |
For stations located on aerodromes: official altitude¹ of the aerodrome. These stations are designated by the letter "A" in the column/field "Other observations and remarks" of Volume A. |
Note: The symbol "#" indicates that the elevation figures are approximate.
| _________________________________ |
| ¹ HP, H and HA are with respect to mean sea level (MSL) which is defined in the International Meteorological Vocabulary (WMO No. 182).
See Guide to Meteorological Instruments and Methods of Observation (WMO-No.8), Part 1, Chapter 1, 1.3.3.2. |
|
| 9. |
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.
Table 1
| Symbol |
Meaning |
| P |
= |
Pilot balloon; observation of upper-wind obtained by optical tracking of a free balloon
|
| R |
= |
Radiosonde; observation of atmospheric pressure, temperature and humidity in the upper-air obtained by electronic means.
|
| W |
= |
Radiowind; upper-wind observation obtained by tracking a free balloon by electronic means
|
| X |
= |
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) |
|
| 10. |
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:
| Station |
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 ) |
|
| 11. |
Remarks
(see: Code Table A) |
Information on additional observations made at the station, special types of stations, and additional information relating to other fields in the data file is shown here. (SeeCode Table A - Observations and Remarksfor an explanation of the abbreviations and symbols used in this field. Reasons for temporary suspension of observing programmes and an expected date of resumptin 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. |
