You can try the grib decoder
wgrib from the Climate Prediction Center of NOAA. It can read and convert grib data to pure binary, IEEE or ASCII text. For example:
Code:
wgrib -s infile | grep ":UGRD:" | wgrib -i -text infile -o outfile
will extract the variable UGRD (zonal winds) and will write it to a text file. Anyway, the conversion to text is very slow and consumes a lot of disk space. Better to convert them to binary and use some high level language (e.g. Fortran) for further processing.
