All data must be encoded following the required rules described below to achieve fully compliant LC-WFV 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 | 19 | The latest WMO table |
| 20 | productionStatusOfProcessedData | 0 | Production data |
| 1 | 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 | WMO subCentre code | Centre acronym*1 |
|---|---|---|---|---|
European Centre for Medium-Range Weather, UK | ECMWF | 98 | N/A | ecmf |
| Met office, UK | UKMO | 74 | N/A | egrr |
| Fleet Numerical Meteorology and Oceanography Center, USA | FNMOC | 58 | N/A | fnmo |
| Environment and Climate Change Canada, Canada | ECCC | 54 | N/A | cwao |
| National Centres for Environmental Prediction, USA | NCEP | 7 | N/A | kwbc |
| Météo France, France | METFR | 84 | N/A | lfpw |
| Deutscher Wetterdienst, Germany | DWD | 78 | N/A | edzw |
| Bureau of Meteorology, Australia | BoM | 1 | N/A | ammc |
| Laboratoire D'Océanographie Physique et Spatiale, France | LOPS | 84 | 202 | lops |
| Japan Meteorological Agency, Japan | JMA | 34 | N/A | rjtd |
| Korea Meteorological Administration, Republic of Korea | KMA | 40 | N/A | rksl |
| Puertos del Estado, Spain | PRTOS | 214 | N/A | lemm |
| Danmarks Meteorologiske Institut, Denmark | DMI | 94 | N/A | ekmi |
National Institute of Water and Atmospheric Research, New Zealand | NIWA | 204 | N/A | niwa |
Det Norske Meteorologiske Institutt, Norway | METNO | 88 | N/A | enmi |
Servicio de Hidrografía Naval, Servicio Meteorológico, Argentina | SHNSM | 41 | N/A | sabm |
New Zealand MetService | NZMS | 69 | N/A | nzkl |
| Servizio Meteorologico dell'Aeronautica Militare, Italy | METEOAM | 80 | N/A | cnmc |
Remarks:
*1 in ECMWF's eCcodes
This example describes an instantaneous field valid on 20120103 00Z from a forecast starting on 20120101 00Z (time step=48 hours) .
| Time ( instantaneous ) | ||||
|---|---|---|---|---|
| Start of forecast ( section 1 ) | ||||
Octets | values | Meaning of values | Grib_api values | |
| 12 | Significance of Reference Time | 1 | Start of forecast | |
| 13-14 | Year (four digits) | 2012 | year of start of forecast | dataDate=20120101 dataTime=0
|
| 15 | Month | 01 | month of start of forecast | |
| 16 | Day | 01 | day of start of forecast | |
| 17 | Hour | 00 | hour of start of forecast | |
| section 4 e.g. template 4.1 | ||||
| 18 | Indicator of unit of time range | 1 | Hour | |
| 19-22 | Forecast time | 48 | Forecast step | stepType=instant, step=48 |
parameter | Sample file |
|---|---|
10 metre U wind component | wave.10u.grib2 |
10 metre V wind component | wave.10v.grib2 |
| Mean wave period based on second moment | wave.mp2.grib2 |
| Mean wave direction | wave.mwd.grib2 |
| Peak wave period | wave.pp1d.grib2 |
Significant height of combined wind waves and swell | wave.swh.grib2 |