This page contains a few rules on the UERRA parameters. A complete list of all the parameters and GRIB2 encoding is given here.
ECMWF makes available a GRIB decoding library (grib_api) for the benefit of the WMO community. grib_api can be freely downloaded from here and the documentation can be found here. The grib_api provides a simplified access to GRIB2 headers through a set of virtual keys documented here.
Octet 36 of section 1 of a GRIB2 message contains the Production status of processed data. The WMO has added two values to table 1.3 Production status of data:
The value 9 should be used when testing and 8 for operational data.
Control and perturbed forecasts are identified in section 1 and 4. The following tables explains how to code them in GRIB2:
Section 1 | |||
---|---|---|---|
Octets | Example perturbed | Example control | |
21 | typeOfProcessedData | =4 | =3 |
Ensemble (section 4, template 4.61) | |||
---|---|---|---|
Octets | Example perturbed | Example control | |
35 | type of ensemble forecast | = 255 (missing) | = 255 (missing) |
36 | perturbation number | = 7 | = 0 |
37 | number of forecasts in ensemble | = 51 | = 51 |
real-time | re-forecast | |
Daily average | Control Perturbed | Control Perturbed |
Accumulations | Control Perturbed | Control Perturbed |
Instantaneous | Control Perturbed | Control Perturbed |
Maximum over the last 6 hours | Control Perturbed | Control Perturbed |
Minimum over the last 6 hours | Control Perturbed | Control Perturbed |