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- The Control Forecast must be number 0,
- The number of members is identical to the number of all EPS members plus the Control Forecast.
GRIB encoding
TIGGE GRIB2 checking tool
The so called tigge_check tool is a part of ecCodes package. It should be used to validate all GRIB2 files prepared for TIGGE. The tool is checking all encoding details so that only fully compliant TIGGE files following exactly required definitions would pass. Find more information about the tool in the page Data encoding checking tools
Encoding
1) TIGGE Production status of processed data
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Octet 20 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:
- 4:TIGGE operational products
- 5: TIGGE test products
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2) Control and perturbed forecasts
Control and perturbed forecasts are identified in section 1 and 4. The following tables explains how to code them in GRIB2:
Section 1 | |||
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Octets | Example perturbed | Example control | |
21 | type of processed data | 4 | 3 |
Ensemble (section 4, template 4.61) | |||
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Octets | Example perturbed | Example control | |
8-9 | product definition template number | 1/11* | 1/11* |
35 | type of ensemble forecast | 255 (missing) | 255 (missing) |
36 | perturbation number | 7 | 0 |
37 | number of forecasts in ensemble | 51 | 51 |
- statistically processed (typeOfStatisticalProcessing is set up)
TIGGE extension (Section 2)
It is proposed that the section 2 for TIGGE fields be the same for all partners. A GRIB2 decoder must decode the section 2 as a TIGGE extension based on the octect 36 of section 1 (Production status of processed data) being 4 or 5.
The format of the TIGGE extension is not yet defined. The section 2 should either be missing or empty.
Checking tool
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Sample data
Data exchange
Naming convention
tigge_CCCC_YYYYMMDDHH_VVVV_LL_NNN.grib2
- CCC: centre acronym (e.g. kwbc for NCEP data)
- YYYYMMDDHH: date * time stamp (e.g. 2019100100 for 0Z run on 2019-10-01)
- VVVV: test/prod
- LL: pl/sl (pressure or surface data)
- NNN: eps number (cf=0, eps1=1,....)