New templates for reforecast in section 4

[sebvi]

Initial request

The following two templates are available to encode reforecasts:

Code	Description
60	Individual ensemble reforecast control and perturbed at a horizontal level or in a horizontal layer at a point in time
61	Individual ensemble reforecast control and perturbed at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval

These 2 templates contains the following set of keys for reforecasts:

number of octets	description
2	Year of Model Version Date
1	Month of Model Version Date
1	Day of Model Version Date
1	Hour of Model Version Date
1	Minute of Model Version Date
1	Second of Model Version Date

We propose to add additional templates which are combinations of existing section 4 templates (2, 12, 99, 100, 103, 104) for specific products extended by the reforecast specific part from templates 60 and 61.

Amendment details

ADD to code table 4.0 Product definition template number

Code	Description
137	Derived reforecast based on all ensemble members at a horizontal level or in a horizontal layer at a point in time
138	Derived reforecast based on all ensemble members at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval
139	Reforecast at a horizontal level or in a horizontal layer at a point in time for waves selected by period range.
140	Individual ensemble reforecast, control and perturbed, at a horizontal level or in a horizontal layer at a point in time for waves selected by period range
141	Reforecast at a horizontal level or in a horizontal layer at a point in time for wave 2D spectra with explicit list of frequencies and directions
142	Individual ensemble reforecast, control and perturbed, at a horizontal level or in a horizontal layer at a point in time for wave 2D spectra with explicit list of frequencies and directions

ADD TEMPLATE 4.137, Derived reforecast based on all ensemble members at a horizontal level or in a horizontal layer at a point in time

Octet	Number of octets	Description
10	1	Parameter Category (see code table 4.1)
11	1	Parameter Number (see code table 4.2)
12	1	Type of Generating Process (see code table 4.3)
13	1	Background Process
14	1	Generating Process Identifier
15- 16	2	Hours After Data Cut-off
17	1	Minutes After Data Cut-off
18	1	Indicator of Unit of Time Range (see code table 4.4)
19- 22	4	Forecast Time
23	1	Type of First Fixed Surface (see code table 4.5)
24	1	Scale Factor of First Fixed Surface
25- 28	4	Scaled Value of First Fixed Surface
29	1	Type of Second Fixed Surface (see code table 4.5)
30	1	Scale Factor of Second Fixed Surface
31-34	4	Scaled Value of Second Fixed Surface
35	1	Derived Forecast (see Code table 4.7)
36-39	4	Number of Forecasts in Ensemble
40-41	2	Year of Model Version Date
42	1	Month of Model Version Date
43	1	Day of Model Version Date
44	1	Hour of Model Version Date
45	1	Minute of Model Version Date
46	1	Second of Model Version Date

ADD TEMPLATE 4.138, Derived reforecast based on all ensemble members at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval

Octet	Number of octets	Description
10	1	Parameter Category (see code table 4.1)
11	1	Parameter Number (see code table 4.2)
12	1	Type of Generating Process (see code table 4.3)
13	1	Background Process
14	1	Generating Process Identifier
15- 16	2	Hours After Data Cut-off
17	1	Minutes After Data Cut-off
18	1	Indicator of Unit of Time Range (see code table 4.4)
19- 22	4	Forecast Time
23	1	Type of First Fixed Surface (see code table 4.5)
24	1	Scale Factor of First Fixed Surface
25- 28	4	Scaled Value of First Fixed Surface
29	1	Type of Second Fixed Surface (see code table 4.5)
30	1	Scale Factor of Second Fixed Surface
31-34	4	Scaled Value of Second Fixed Surface
35	1	Derived Forecast (see Code table 4.7)
36-39	4	Number of Forecasts in Ensemble
40-41	2	Year of Model Version Date
42	1	Month of Model Version Date
43	1	Day of Model Version Date
44	1	Hour of Model Version Date
45	1	Minute of Model Version Date
46	1	Second of Model Version Date
47-48	2	Year of end of overall time interval
49	1	Month of end of overall time interval
50	1	Day of end of overall time interval
51	1	Hour of end of overall time interval
52	1	Minute of end of overall time interval
53	1	Second of end of overall time interval
54	1	n - number of time range specifications describing the time intervals used to calculate the statistically processed field
55-58	4	Total number of data values missing in statistical process
		59 - 70 Specification of the outermost (or only) time range over which statistical processing is done
59	1	Statistical process used to calculate the processed field from the field at each time increment during the time range (see code table 4.10)
60	1	Type of time increment between successive fields used in the statistical processing (see code table 4.11)
61	1	Indicator of unit of time for time range over which statistical processing is done (see code table 4.4)
62-65	4	Length of the time range over which statistical processing is done, in units defined by the previous octet
66	1	Indicator of unit of time for the increment between the successive fields used (see code table 4.4)
67-70	4	Time increment between successive fields, in units defined by the previous octet
		71 - nn These octets are included only if n > 1, where nn = 59+ 12 x n
71-82	12	As octets 59 to 70, next innermost step of processing
83-nn	n/a	Additional time range specifications, included in accordance with the value of n. Contents as octets 59 to 70, repeated as necessary

ADD TEMPLATE 4.139, Reforecast at a horizontal level or in a horizontal layer at a point in time for waves selected by period range.

Octet	Number of octets	Description
10	1	Parameter Category (see code table 4.1)
11	1	Parameter Number (see code table 4.2)
12	1	Type of Wave Period Interval (see code table 4.91)
13	1	Scale Factor of Lower Wave Period Limit
14 -17	4	Scaled Value of Lower Wave Period Limit
18	1	Scale Factor of Upper Wave Period Limit
19-22	4	Scaled Value of Upper Wave Period Limit
23	1	Type of Generating Process (see code table 4.3)
24	1	Background Process
25	1	Generating Process Identifier
26-27	2	Hours After Data Cut-off
28	1	Minutes After Data Cut-off
29	1	Indicator of Unit of Time Range (see code table 4.4)
30-33	4	Forecast Time
34	1	Type of First Fixed Surface (see code table 4.5)
35	1	Scale Factor of First Fixed Surface
36-39	4	Scaled Value of First Fixed Surface
40	1	Type of Second Fixed Surface (see code table 4.5)
41	1	Scale Factor of Second Fixed Surface
42-45	4	Scaled Value of Second Fixed Surface
46-47	2	Year of Model Version Date
48	1	Month of Model Version Date
49	1	Day of Model Version Date
50	1	Hour of Model Version Date
51	1	Minute of Model Version Date
52	1	Second of Model Version Date

ADD TEMPLATE 4.140, Individual ensemble reforecast, control and perturbed, at a horizontal level or in a horizontal layer at a point in time for waves selected by period range

Octet	Number of octets	Description
10	1	Parameter Category (see code table 4.1)
11	1	Parameter Number (see code table 4.2)
12	1	Type of Wave Period Interval (see code table 4.91)
13	1	Scale Factor of Lower Wave Period Limit
14 -17	4	Scaled Value of Lower Wave Period Limit
18	1	Scale Factor of Upper Wave Period Limit
19-22	4	Scaled Value of Upper Wave Period Limit
23	1	Type of Generating Process (see code table 4.3)
24	1	Background Process
25	1	Generating Process Identifier
26-27	2	Hours After Data Cut-off
28	1	Minutes After Data Cut-off
29	1	Indicator of Unit of Time Range (see code table 4.4)
30-33	4	Forecast Time
34	1	Type of First Fixed Surface (see code table 4.5)
35	1	Scale Factor of First Fixed Surface
36-39	4	Scaled Value of First Fixed Surface
40	1	Type of Second Fixed Surface (see code table 4.5)
41	1	Scale Factor of Second Fixed Surface
42-45	4	Scaled Value of Second Fixed Surface
46	1	Type of Ensemble Forecast (see code table 4.6)
47-50	4	Perturbation Number
51-54	4	Number of Forecasts in Ensemble
55-56	2	Year of Model Version Date
57	1	Month of Model Version Date
58	1	Day of Model Version Date
59	1	Hour of Model Version Date
60	1	Minute of Model Version Date
61	1	Second of Model Version Date

ADD TEMPLATE 4.141, Reforecast at a horizontal level or in a horizontal layer at a point in time for wave 2D spectra with explicit list of frequencies and directions

Octet	Number of Octets	Description
10	1	Parameter Category (see code table 4.1)
11	1	Parameter Number (see code table 4.2)
12-13	2	Wave Direction Number
14-15	2	Number of Wave Directions – ND
16-17	2	Wave Frequency Number
18-19	2	Number of Wave Frequencies – NF
20	1	Type of Generating Process (see code table 4.3)
21	1	Background Process (defined by originating centre)
22	1	Generating Process Identifier (defined by originating centre)
23-24	2	Hours After Data Cut-off (see Note)
25	1	Minutes After Data Cut-off
26	1	Indicator of Unit of Time Range (see code table 4.4)
27-30	4	Forecast Time
31-32	2	Year of Model Version Date
33	1	Month of Model Version Date
34	1	Day of Model Version Date
35	1	Hour of Model Version Date
36	1	Minute of Model Version Date
37	1	Second of Model Version Date
38	1	Scale Factor of Wave Directions
		The following entry of 4 octets is repeated ND times. (ND is defined in octets 14-15)
39 + (ND-1)*4 –42 + (ND-1)*4	4	Scaled Values of Wave Directions
43 + (ND-1)*4	1	Scale Factor of Wave Frequencies
		The following entry of 4 octets is repeated NF times. (NF is defined in octets 18-19)
44 +(ND-1)*4 + (NF-1)*4-47 +(ND-1)*4 + (NF-1)*4	4	Scaled Values of Wave Frequencies

ADD TEMPLATE 4.142, Individual ensemble reforecast, control and perturbed, at a horizontal level or in a horizontal layer at a point in time for wave 2D spectra with explicit list of frequencies and directions

Octet	Number of Octets	Description
10	1	Parameter Category (see code table 4.1)
11	1	Parameter Number (see code table 4.2)
12-13	2	Wave Direction Number
14-15	2	Number of Wave Directions – ND
16-17	2	Wave Frequency Number
18-19	2	Number of Wave Frequencies – NF
20	1	Type of Generating Process (see code table 4.3)
21	1	Background Process (defined by originating centre)
22	1	Generating Process Identifier (defined by originating centre)
23-24	2	Hours After Data Cut-off (see Note)
25	1	Minutes After Data Cut-off
26	1	Indicator of Unit of Time Range (see code table 4.4)
27-30	4	Forecast Time
31	1	Type of Ensemble Forecast (see code table 4.6)
32-35	4	Perturbation Number
36-39	4	Number of Forecasts in Ensemble
40-41	2	Year of Model Version Date
42	1	Month of Model Version Date
43	1	Day of Model Version Date
44	1	Hour of Model Version Date
45	1	Minute of Model Version Date
46	1	Second of Model Version Date
47	1	Scale Factor of Wave Directions
		The following entry of 4 octets is repeated ND times. (ND is defined in octets 14-15)
48 + (ND-1)*4 –51 + (ND-1)*4	4	Scaled Values of Wave Directions
52 + (ND-1)*4	1	Scale Factor of Wave Frequencies
		The following entry of 4 octets is repeated NF times. (NF is defined in octets 18-19)
53 +(ND-1)*4 + (NF-1)*4-56 +(ND-1)*4 + (NF-1)*4	4	Scaled Values of Wave Frequencies

Comments

No response

Requestor(s)

Sebastien Villaume (ECMWF)
Robert Osinski (ECMWF)

Stakeholder(s)

ECMWF

Publication(s)

Manual on Codes (WMO-No. 306), Volume I.2, GRIB code table 4.0 (update)
Manual on Codes (WMO-No. 306), Volume I.2, GRIB Template 4.137 (create)
Manual on Codes (WMO-No. 306), Volume I.2, GRIB Template 4.138 (create)
Manual on Codes (WMO-No. 306), Volume I.2, GRIB Template 4.139 (create)
Manual on Codes (WMO-No. 306), Volume I.2, GRIB Template 4.140 (create)
Manual on Codes (WMO-No. 306), Volume I.2, GRIB Template 4.141 (create)
Manual on Codes (WMO-No. 306), Volume I.2, GRIB Template 4.142 (create)

Expected impact of change

None

Collaborators

No response

References

No response

Validation

No response

[amilan17]

https://github.com/wmo-im/tt-tdcf/wiki/2024.11.13.tt.tdcf notes:

• Sebastien introduced the proposal
• @wmo-im/tt-tdcf please review and comment on this proposal

[sebvi]

Please find attached some sample files and a version of ecCodes capable of encode/decode the new proposed templates.
eccodes-2.40.0-Source.tar.gz
FT2025-1_280.tar.gz

[amilan17]

ttps://github.com/wmo-im/tt-tdcf/wiki/2024.11.12.tt.tdcf notes:
@sebvi branch is ready for updates;