We have transitioned the data files from netCDF3 to netCDF4-classic format on Monday Oct 20th. As a result, the files will be compressed instead of being packed with a scale and offset. As with any netCDF4 file, the NetCDF library will perform the uncompression. We expect the files to be read faster, depending on the application you are using. Values may differ slightly because of precision issues. Please let us know if you run into any problems after first reading our netCDF4 doc. We are also changing the time units to use 1800 as the origin year for udunits. This should prove easier for users. The exception to the above are the spectral coefficients files, which are still packed.