GRIB2 - PRODUCT DEFINITION TEMPLATE 4.9

Probability forecasts at a horizontal level or in a horizontal
layer in a continuous or non-continuous time interval

Created 09/21/2007


Octet No. Contents
10
 Parameter category (see Code Table 4.1)
11
 Parameter number (see Code Table 4.2)
12
 Type of generating process (see Code Table 4.3)
13
 Background generating process identifier (defined by originating centre)
14
 Forecast generating process identifier (see Code ON388 Table A)
15-16
 Hours after reference time data cutoff (see Note 1)
17
 Minutes after reference time data cutoff
18
 Indicator of unit of time range (see Code Table 4.4)
19-22
 Forecast time in units defined by octet 18 (see Note 2)
23
 Type of first fixed surface (see Code Table 4.5)
24
 Scale factor of first fixed surface
25-28
 Scaled value of first fixed surface
29
 Type of second fixed surfaced (see Code Table 4.5)
30
 Scale factor of second fixed surface
31-34
 Scaled value of second fixed surfaces
35
 Forecast probability number
36
 Total number of forecast probabilities
37
 Probability Type (see Code Table 4.9)
38
 Scale factor of lower limit
39-42
 Scaled value of lower limit
43
 Scale factor of upper limit
44-47
 Scaled value of upper limit
48-49
 Year of end of overall time interval
50
 Month of end of overall time interval
51
 Day of end of overall time interval
52
 Hour of end of overall time interval
53
 Minute of end of overall time interval
54
 Second of end of overall time interval
55 n ― number of time ranges specifications describing the time intervals used to calculate the statistically-processed field
56-59
 Total number of data values missing in the statistical process
60 - 71 Specification of the outermost (or only) time range over which statistical processing is done
60
 Statistical process used to calculate the processed field from the field at each time increment during the time range (see Code Table 4.10)
61
 Type of time increment between successive fields used in the statistical processing (see Code Table 4.11)
62
 Indicator of unit of time for time range over which statistical processing is done (see Code Table 4.4)
63-66
 Length of the time range over which statistical processing is done, in units defined by the previous octet
67
 Indicator of unit of time for the increment between the successive fields used (see Code Table 4.4)
68-71 Time increment between successive fields, in units defined by the previous octet (see Note 3)
72-nn These octets are included only if n>1, where nn = 59 + 12 x n
72-83
 As octets 60 to 71, next innermost step of processing
84-nn
 Additional time range specifications, included in accordance with the value of n. Contents as octets 60 to 71, repeated as necessary


Notes:

(1) Hours greater than 65534 will be coded as 65534.
(2) The reference time in section 1 and the forecast time together define the beginning of the overall time interval.
(3) An increment of zero means that the statistical processing the result of continuous (or near continuous) process, not the processing of a number of discrete samples. Examples of such continuous process are the temperatures measured by analogue maximum and minimum thermometers or thermographs and the rainfall measured by a rain gauge.
The reference and forecast times are successively set to their initial plus or minus the increment, as defined by the type of time increment (one of octets 48,60,72...). For all but the innermost (last) time range, the next inner range is then processed using these reference and forecast times as the initial reference and forecast time.


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