In progress. All details still to be updated.. |
All data must be encoded following the required rules described below to achieve fully compliant LC-GCR format from all centres.
ECMWF makes available a GRIB decoding library (ecCodes) for the benefit of the WMO community. ecCodes can be freely downloaded from here and the documentation can be found here.
For more general information about GRIB2 format please refer to WMO Manual on Codes .
Specific details which should be encoded in GRIB2 sections 1 and 4:
| Section 1 | |||
|---|---|---|---|
| Octets | Key name | Value | Description |
| 6-7 | centre | X | WMO Centre's code (table below) |
| 8-9 | subCentre | X | WMO Sub-Centre's code if needed (table below) |
| 10 | tablesVersion | X | The latest WMO table |
| 20 | productionStatusOfProcessedData | 14 | Production data |
| 15 | Test data | ||
| 21 | typeOfProcessedData | 0 | Analysis products |
| 1 | Forecast products | ||
| Section 4 | |||
|---|---|---|---|
| Octets | Key name | Value | Description |
| 8-9 | productDefinitionTemplateNumber | 0 | Analysis and Forecast products (instantaneous) (Analysis or forecast at a horizontal level or in a horizontal layer at a point in time (grib2/tables/17/4.0.table)) |
The codes below are based on WMO Manual 306 - WMO Codes. Each organization must be uniquely identified by its WMO code. If necessary to distinguish between two organizations using the same WMO code the Sub-Centre one which differs must be provided.
| Organisation | Acronym | WMO Centre code | Centre acronym*1 |
|---|---|---|---|
China Meteorological Administration, China | CMA | babj | |
European Centre for Medium-Range Weather, UK | ECMWF | 98 | ecmf |
| Japan Meteorological Agency, Japan | JMA | 34 | rjtd |
| National Centres for Environmental Prediction, USA | NCEP | 7 | kwbc |
| National Aeronautics and Space Administration | NASA | nasa |
Remarks:
*1 in ECMWF's ecCodes package
parameter | Sample file | GRIB metadata dump*1 |
|---|---|---|
Time-mean 2 metre temperature | ecmf.an.grib2 | ecmf.an.txt |
Time-mean mean sea level pressure | ||
| Time-mean total precipitation | ecmf.fc.tp.grib2 | ecmf.fc.tp.txt |
*1 using "grib_dump -O" command from ecCodes package
Remarks