WMO Publication No. 9

Volume A
Observing Stations

 

RECORD LAYOUT
OF THE
MASTER FLAT FILE

 

May 1998 edition

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Table of Contents

Introduction

Table of Contents

Record Layout of the master Station Data File (Pub9volA9yymmdd.flatfile)

Code tables (see separate file):

· Table A. Observations and Remarks: Explanation of the symbols and abbreviations used in the "Observations and Remarks" field.

· Table B. Footnote Texts: List of the footnote texts found in the publication, and their corresponding code numbers

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Introduction

WMO Publication No. 9 Volume A - Observing Stations contains a complete list of the surface and upper-air weather observing stations in operation which are used for synoptic purposes.

The Volume A data file is now produced in a new format. This guide explains the layout of this data file, and describes the fields in each record.

Two code tables (A and B) are also available at the WMO Web site to be used (A) as a reference guide to the codes and symbols used in the data file and (B) to the footnote codes used.

NEW COUNTRY CODE FIELD:

A new field was added to the data files in March 1998 to respond to user requests. Following field No. 3 "Country Area", a new field No. 4 "Country Code" has been added (and the following fields renumbered 5 to 29 instead of 4 to 28). The Country Code number in this field is the same code number used in the former data files (prior to May 1997) to identify the country in which the station is located. This is provided to make importing the data files easier for those users whose computer systems are set up according to the old country numbering system.

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Record Layout of the
Station Data File
(Pub9volA9yymmdd.flatfile)

 1. Description of contents:

The data file "Pub9volA9yymmdd.flatfile" is the master Station Data file. It contains the information on the station name and identification number, location, elevation/pressure, the types and times of observations carried out, as well as additional notes and remarks regarding the station and its observations.

 2. Languages:

Since Volume A is issued as a bilingual publication, the text in several of the data fields is in both English and French (e.g. region name, country name, footnotes - see Code Table B).

 3. Format of data file:

The data file is in ASCII code, in tab-delimited format (i.e. the fields of each record are separated by tabs).

4. Record and field structure:

All the data concerning each station is contained in one record in the master Station Data file. This includes the station name, number, and location; the country and region to which the station belongs; and data about the station's observations (for an explanation of the symbols in the "Observations and Remarks" field, see Code Table A). Each of these records is composed of 29 fields (even if some fields are left blank because there is no data for those fields). Each field contains a specific type of data related to the station. The fields of each record are separated by tabs (the "field delimiter"). The layout of the records, with the order and code names of the fields, is illustrated in the following record model (">" = tab character):

1.RegionId > 2.RegionName > 3.CountryArea > 4.CountryCode > 5.StationId > 6.IndexNbr > 7.IndexSubNbr > 8.StationName > 9.Lat > 10.Long > 11.Hp > 12.HpFlag > 13.Hha > 14.HhaFlag > 15.PressureDefId > 16.SO-1 > 17.SO-2 > 18.SO-3 > 19.SO-4 > 20.SO-5 > 21.SO-6 > 22.SO-7 > 23.SO-8 > 24.ObsHs > 25.UA-1 > 26.UA-2 > 27.UA-3 > 28.UA-4 > 29.ObsRems

5. Sample record:

The data in each of the records in the Station Data file appears like in the following sample record:

1 > AFRICA / AFRIQUE > SUDAN / SOUDAN > 1160 > 382 > 62781 > 0 > EN NAHUD > 12 42N > 28 26E > 564 > > 565 > # > > X > X > X > X > X > X > X > X > S0024 > . > . > . > . > CLIMAT(C);EVAP;M/B;SUNDUR

 In the printed edition of Volume A, the above sample record appears as follows:

REGION I - AFRICA / AFRIQUE
SUDAN / SOUDAN

INDEX NUMBER

NAME

LAT.

LONG.

ELEVATION
HP H/HA

PRESSURE LEVEL

SURFACE OBSERVATIONS
00 03 06 09 12 15 18 21

OBS.H
OBS.S

UPPER-AIR
00 06 12 18

OTHER OBSERV. AND REMARKS 

62781

EN NAHUD

12 42N

28 26E

564 565#

 

X _X _X _X _X _X _X _X

S00-24

_. _. _. _.

CLIMAT(C);EVAP;M/B;SUNDUR

6. Data fields - order and contents:

The 29 data fields of each record are listed in order in the table below. For each field, the field code name is given along with the field definition, as well as an explanation of the contents, including the symbols, if any, that are used in that particular field.

Station Data file - Summary of field layout and contents

Type of data

Field No.

Field Code Name

Definition of Field Contents

Symbols used

Explanation of Field Contents and/or Description of Symbols Used

Region

 

1

RegionId

WMO region number

 

 

2

Region Name

Name of WMO region

 

Region name, in English and French

Country

 

3

Country Area

Name of country or area

 

Country or area (in English and French) in which station is located.

4

Country Code

Code number of country or area

 

Code number used in pre-May 1997 data files to identify the country or area of a station.

Station
identification

 

5

StationId

Station identifier number

 

The station identifier is the "KeyField Value" used by the data base

6

IndexNbr

WMO Station Index Number (a)

 

Unique station identifier, used in the transmission of weather observation reports from the station.(a)

7

Index SubNbr

Sub-index number

 

A sub-index number is inserted for each station. It is used in the data file to differen-tiate 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

8

Station Name

Name of station

 

Station's name, assigned by the country

Location

9

 

Lat

 

Latitude

 

 

 

Latitude, in degrees and minutes:

N

North of the Equator

S

South of the Equator

10

 

Long

 

Longitude

 

 

Longitude, in degrees and minutes:

E

East of the Greenwich meridian

W

West of the Greenwich meridian

Elevation / Pressure level

11

Hp

Elevation of the station, in metres

 

Elevation of the station, in metres; the reference/datum level to which barometric pressure reports at the station refer.

12

HpFlag

Indicates approximate figure

#

A hash sign ("#") is inserted if the elevation figure shown for HP is approximate.

13

Hha

Elevation or Altitude: H or HA, in metres

 

 

H: For stations not located on aerodromes: elevation of the ground (average level of terrain in the immediate vicinity of the station).

 

HA: For stations located on aerodromes: official altitude of the aerodrome. These stations are designated by the letter "A" in the column/field "Other observations and remarks" (see Field 29 below, and Code Table A - Observations and Remarks).

14

HhaFlag

Indicates approximate figure

#

A hash sign ("#") appears if the elevation figure shown for H or HA is approximate.

15

 

PressureDefId

Pressure level

 

 

For stations which do not indicate air pressure reduced to mean sea level in their synoptic reports (group 4PPPP), the following indicators show the information reported in lieu of group 4PPPP:

STATION

Pressure at station level is reported using group 3PoPoPoPo.

1000 HPA

850 HPA

700 HPA

500 HPA

Geopotential of the given standard isobaric surface is reported using group 4a3hhh.

Surface observations

 



16

17

18

19

20

21

22

23



SO-1

SO-2

SO-3

SO-4

SO-5

SO-6

SO-7

SO-8

Surface synoptic observations:
at 00 UTC

at 03 UTC

at 06 UTC

at 09 UTC

at 12 UTC

at 15 UTC

at 18 UTC

at 21 UTC

X

Surface synoptic observations are made regularly at the time indicated, in accordance with a fixed schedule.

(figures)

Time figures shown instead of an X (e.g. "02" under column "03" / in field "SO2") mean that observations are made regularly at the time inserted (e.g. 0200 UTC) instead of at the standard observation time for the corresponding column/field (in this case 0300 UTC).

.
(dot)

No surface observations are made at the time indicated.

24

 

ObsHs

 

Hourly or Half-hourly surface observations

 

 

 

If surface observations are made on an hourly or half-hourly basis, this is indicated by the symbol H or S, followed by the period of the day during which this is done. When the period begins or ends at the half-hour, the full four-figure time is given.

H

Hourly observations are carried out during the period indicated.

S

Half-hourly (semi-hourly) observations are carried out during the period indicated.

Upper-air observations

 

 

 



25

26

27

28

 



UA-1

UA-2

UA-3

UA-4

 

Upper-air observations:
at 00 UTC

at 06 UTC

at 12 UTC

at 18 UTC

 

X

Upper-air observation of an unspecified type is carried out.

(figures)

The symbol "X" is replaced by figures indicating a time (e.g. 23, 02, etc.) when the observation is carried out at a non-standard time.

P

Pilot-balloon: observation of upper-wind is obtained by optical tracking of a free balloon.

R

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

W

Radiowind: upper-wind observation is obtained by tracking a free balloon by electronic means.

WP

Wind Profiler: a wind profiler is used to obtain the upper-air observation.

PR

RW

The letters P, R and W are combined as necessary to indicate simultaneous upper-air observations of the different types listed above.

.
(dot)

No upper-air observations are made at the time indicated.

Additional information

29

ObsRems

Other observations and 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. (See Code Table A - Observations and Remarks for an explanation of the abbreviations and symbols used in this field.)