Introduction

The grib variable table that is built in to wgrib2 is based on the NCEP table and entries from other centers. For the WMO-defined entries, NCEP names are used. You may want to change the grib table because

1. grib table is incomplete
2. you want to use names that make sense
3. the center's names for locally defined fields are not included in wgrib2
4. you want to use an unofficial table

https://www.cpc.ncep.noaa.gov/products/wesley/wgrib2/user_grib2tables.html

Now the -gribtable_used option helps you set up the user grib table. The option writes grib table entries used by a file.

Usage

-gribtable_used OUTPUT
     OUTPUT is a file with the grib table entries for each field

Example

$ wgrib2 gep19.t00z.pgrb2af180 -gribtable_used junk
1:0:d=2009060500:HGT:200 mb:180 hour fcst:ENS=+19
2:46042:d=2009060500:TMP:200 mb:180 hour fcst:ENS=+19
3:63079:d=2009060500:RH:200 mb:180 hour fcst:ENS=+19
..

$ sort -u junk > grbtbl     (get rid of duplicate entries)
edit grbtbl, change UGRD to U, VGRD to V and TMP to T

$ export grib2table=`pwd`/grbtbl      (define a user grib table)

$ wgrib2 gep19.t00z.pgrb2af180 -match '(U|V|T)'
1:0:d=2009060500:HGT:200 mb:180 hour fcst:ENS=+19
2:46042:d=2009060500:T:200 mb:180 hour fcst:ENS=+19
3:63079:d=2009060500:RH:200 mb:180 hour fcst:ENS=+19
4.1:86046:d=2009060500:U:200 mb:180 hour fcst:ENS=+19
4.2:86046:d=2009060500:V:200 mb:180 hour fcst:ENS=+19
5:137483:d=2009060500:HGT:250 mb:180 hour fcst:ENS=+19
6:184669:d=2009060500:T:250 mb:180 hour fcst:ENS=+19
..

Note: U and V will not be treated as vectors in -new_grid.  You have
to use -new_grid_vectors to get U and V to be vectors.

See also: -new_grid, -new_grid_vectors, user_grib2tables