David, The grib package doesn't create grib but there's a grib filter method that permits one to extract records from a grib file based on parameter criteria and outputs another grib file. These filters are used internally where I wanted test files with certain type of data. The methods are limited in that they can only filter one parameter at a time but multiple runs with the output appended to each other might be an option. The methods are Grib2ExtractRawData and Grib1ExtractRawData. Interpolation could be done if I had the time, currently I'm booked for the next year. The package has just been through a major refactor and the latest distribution is in alpha testing. I would appreciate any comments on how the code is preforming. The dist is at: http://www.unidata.ucar.edu/software/decoders/ The release version grib-decoder-java_8.0.1.tar.gz or GRIBJava.tar.gz Thanks, RObb... Ticket Details =================== Ticket ID: MYG-785641 Department: Support netCDF Java Priority: High Status: Open