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 | values | meaning of values | Grib_api keys | |
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 | |
Daily average ( section 4 e.g. template 4.11 ) | ||||
18 | Indicator of unit of time range | 1 | Hour | |
19-22 | Forecast time | 24 | Start of forecast + forecast time = start of average period | startStep=24 |
38-39 | year of end of overall time interval | 2012 |
End of average period |
endStep=-48 |
40 | month of end of overall time interval | 01 | ||
41 | day of end of overall time interval | 03 | ||
42 | hour of end of overall time interval | 00 | ||
45 | number of time ranges | 1 | Only one time statistics applied (average) | |
46-49 | total number of data values missing in statistical process | 0 | ||
50 | Statistical process used to calculate the processed field from the field at each time increment during the time range | 0 | Average | stepType=avg |
51 | Type of time increment between successive fields used in the statistical processing | 2 | Successive times processed have same start time of forecast, forecast time is incremented | |
52 | Indicator of unit of time for time range over which statistical processing is done | 11 | 6-hourly | indicatorOfUnitOfTimeRangeindicatorOfUnitForTimeRange=11 |
53-56 | Length of the time range over which statistical processing is done, in units defined by the previous octet | 4 | Daily average | lengthOfTimeRange=4 |
57 | Indicator of unit of time for the increment between the successive fields used | 11 | 6-hourly | indicatorOfUnitForTimeIncrement=11 |
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: