This example represents a daily average valid on 2 January 2012 of a field produced by a real-time forecast started on 20120101 00Z. In this example, where the field is produced 6-hourly, the daily average valid on 20120102 is the average of steps 24, 30, 36 and 42.
- In bold, the values are fixed. They are meant to be used by all partners
- In green, these are the values for the example.
Time ( daily average ) | |||||||||
---|---|---|---|---|---|---|---|---|---|
Start of forecast ( section 1 ) | |||||||||
Octets reforecast Octets real time | values | Fixed | meaning of values | Grib_api keys | |||||
Example | 12 | 12 | Significance of Reference Time | =1 | Start of forecast | = 1 | |||
13-14 | 13-14 | Year (four digits) | 2012 | year of start of forecast | dataDate= | 201220120101 | 15dataTime=0 | ||
15 | Month | 01 | month of start of forecast | = 01||||||
16 | 16 | Day | 01 | day of start of forecast | = 01 | 17 | |||
17 | Hour | 00 | hour of start of forecast | = 00||||||
Daily average ( section 4 e.g. template 4.11 ) | 18|||||||||
18 | Indicator of unit of time range | = 11 | Hour | = 1 | |||||
19-22 | 19-22 | Forecast time | 24 | Start of forecast + forecast time = start of average period | startStep=24 | 45-46||||
38-39 | year of end of overall time interval | 2012 |
End of average period |
endStep= | 2012-48 | ||||
47 | 40 | month of end of overall time interval | = | 01 | |||||
48 | 41 | day of end of overall time interval | = | 03 | 49|||||
42 | hour of end of overall time interval | = | 00 | 52||||||
45 | number of time ranges | = 4 6 hourly fields used in average | 53-561 | Only one time statistics applied (average) | |||||
46-49 | total number of data values missing in statistical process | = 00 | = 0 | ||||||
57 | 50 | Statistical process used to calculate the processed field from the field at each time increment during the time range | = 00 | Average | stepType= 0avg | ||||
58 | 51 | Type of time increment between successive fields used in the statistical processing | = 22 | Successive times processed have same start time of forecast, forecast time is incremented | = 2 | ||||
59 | 52 | Indicator of unit of time for time range over which statistical processing is done | = 1 | Hour | = 1 | 60-6311 | 6-hourly | indicatorOfUnitForTimeRange=11 | |
53-56 | Length of the time range over which statistical processing is done, in units defined by the previous octet | = 244 | Daily average | lengthOfTimeRange= 244 | |||||
64 | 57 | Indicator of unit of time for the increment between the successive fields used | = 1 | Hour | = 1 | 11 | 6-hourly | indicatorOfUnitForTimeIncrement=11 | |
65-68 | 58-61 | Time increment between successive fields, in units defined by the previous octet | 1 | Time frequency used to compute the daily mean | In the example, 1 means that 6-hourly outputs have been used to compute the average | timeIncrement=1 |
Examples of GRIB2 headers: