Introduction

Please see new grib for the basic concepts of making new grib files.

The -set option changes specific metadata of the in-memory grib (sub-)message. You need to save the messages to make them permanent. Expect the list of supported fields to expand as needed. There is some overlap between various -set_* options and the -set option. (Ex. -set_center N, and -set center N.) The -set option is the newer method. The -set option is used by the -set_metadata option.

Parameters that can be set

The available parameters that can be set will depend on the version of wgrib2 being used. To see the parameter available,

$ wgrib2 grib_file -set junk junk
*** FATAL ERROR: set asdf, allowed values: discipline, center, subcenter, master_table, 
local_table, background_process_id, analysis_or_forecast_process_id, aerosol_size, 
aerosol_wavelength, process, model_version_date, chemical, aerosol, table_1.2, table_1.3, 
table_1.4, table_3.0, table_3.1/GDT, table_3.2, table_3.3, table_3.4, table_4.0/PDT, 
table_4.1, table_4.2, table_4.3, table_4.5a, table_4.5b, table_4.6, table_4.7, table_4.8, 
table_4.10, table_4.11, table_4.230, table_4.233, table_5.0/DRT, table_6.0, %, cluster ***

Usage

-set X Y             X=field, Y=integer/float/long long int
                     depending on X

                     To find the values of X, use: wgrib2 - -set help all

Fields (as of wgrib2 v2.0.1)

1. discipline or table_0.0 (fixed v2.0.5)
2. center
3. subcenter
4. master_table or table_1.0
5. local_table or table_1.1
6. background_process_id
7. analysis_or_forecast_process_id
8. aerosol_size
9. aerosol_wavelength
10. process
11. model_version_date
12. chemical
13. aerosol
14. table_1.2
15. table_1.3
16. table_1.4
17. table_3.0
18. table_3.1 or GDT
19. table_3.2
20. table_3.3
21. table_3.4
22. table_4.0 or PDT
23. table_4.1
24. table_4.2
25. table_4.3
26. table_4.5a
27. table_4.5b
28. table_4.6
29. table_4.7
30. table_4.8
31. table_4.10
32. table_4.11
33. table_4.230
34. table_4.233
35. table_5.0 or DRT
36. table_6.0
37. %
38. cluster

Fields

1. most are obvious and take an integer argument
2. %: integer 0..100, percentage forecast
3. model_version_date: YYYYMMDDHHmmss, for PDT 4.60 and 4.61

Example

$ wgrib2 IN.grb -set center 99 -center -grib OUT.grb
1:0:center=De Bilt, Netherlands
2:46042:center=De Bilt, Netherlands
3:63079:center=De Bilt, Netherlands
4.1:86046:center=De Bilt, Netherlands
...

-set center 99       sets the "center" to a value of 99 for current grib message (De Bilt)
-center              prints the value of "center"
-grib OUT.grb        writes the current grib message to OUT.grb
                     note: -grib uses the original compressesed grid values
		       -grib_out recompresses the grid values