The -AAIG option writes the data into a Ascii ArcInfo Grid file. This option is experimental and only supports equally spaced lat-lon
grids. Each field is written to different file in the current directory.
wgrib2 in_file -match ':HGT:400 mb:' -AAIG
The above line converts all the 400 mb HGT fields into an
arcinfo ascii grid file.
See also: -csv