GRIB2 - PRODUCT DEFINITION TEMPLATE 4.131

Anomalies significance and other derived products as probability forecasts in relation to a reference period
at a horizontal level or in a horizontal layer at a point in time

Created 09/23/2025


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
Analysis or forecast generating process identifier (see ON388 Table A)
15-16
Hours of observational data cut-off after reference time (see Note 1)
17
Minutes of observational data cut-off after reference time
18
Indicator of unit of time range (see Code table 4.4)
19-22
Forecast time in units defined by octet 18
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 surface (see Code table 4.5)
30
Scale factor of second fixed surface
31-34
Scaled value of second fixed surface
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
Type of reference dataset (see Code table 4.100)
49
Type of relation to reference dataset (see Code table 4.101)
50
Number of additional parameters for reference period (NA) (see Note 2)

The next two entries are repeated NA times na=0:NA - can be 0 times if no parameters are necessary
51+(na-1)*5
Scale factor of additional parameters for reference period
(52+(na-1)*5)-(55+(na-1)*5)
Scaled value of additional parameters for reference period

End of repeated NA sequence
(51+NA*5)-(52+NA*5)
Year of start of reference period
53+NA*5
Month of start of reference period
54+NA*5
Day of start of reference period
55+NA*5
Hour of start of reference period
56+NA*5
Minute of start of reference period
57+NA*5
Second of start of reference period
(58+NA*5)-(61+NA*5)
Sample size of reference period
62+NA*5
Number of reference period time range (NR) (see Note 3)

The next three entries are repeated NR times nr=1:NR
63+NA*5+(nr-1)*6
Type of statistical processing for time range for reference period (see Code table 4.102)
64+NA*5+(nr-1)*6
Indicator of unit of time range for reference period (see Code table 4.4)
(65+NA*5+(nr-1)*6)-(68+NA*5+(nr-1)*6)
Length of time range for reference period

End of repeated NR sequence


Notes:

(1)  Hours greater than 65534 will be coded as 65534

(2)  See notes under Code table 4.101 for details.

(3)  'Number of reference period time range' is used to define an outer and, if needed, one or more inner loops. The outer loop gives the overall date and time range of the reference period and the inner loop(s) specify a sub-period over all time instances defined in the outer loop in terms of the time unit defined by 'Reference period indicator of unit for time increment'. Typically the outer loop defines a number of years and inner loop defines the date and time range within each year: for instance 'every January for 30 years'.


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