Introduction

Wgrib2 v2.0.8 has the typical bug fixes, updates for tables, minor enhancements. All these can found in the change log. Here are the bigger changes.

The interpolattion library has been changed from the single precision grib1 to the newer double precision grib2 library. The newer library is more accurate and supports rotated lat-lon grids. Both Canada and NCEP plan to join the Europeans in making rotated lat-lon grib files.

I am working with 80 member ensembles, so gmerge had to be modified to handle 80 input files, and -ens_processing option was written to get the ensemble statistics.

Everybody has a program/script to add an offset to a date code. Unlike other solutions, the offset can be in minutes, hours, days, months and even years. (-ndate)

The -ndate option was ok, but puting it into a do loop makes scripting much easier when doing time loops (-ndates). I immediately rewrote scriopts to use -ndates. It isn't the best design to have -ndate and -ndates in wgrib2. However, it was a low cost solution assuming wgrib2 has to be ported to the new machine.

I learned how to use the unix command "seq" to generate a list of 80 ensemble members by changing the seq format. So I added -ndates_fmt to generate lists of files of uniformly varying dates.

The time has come to support minute units. Originally wgrib2 did not supoort minute units because the minutes units is "mn" which could be confused with month. (wgrib2 uses GrADS units.)

NetCDF4 is not working well. The problem is compiling the HDF5 library with newer versions of gcc. You may use the Intel compiler. Another option is to find the system HDF5 library and modify the makefile. I expect the next version of HDF5 will address the problems.

Compiling wgrib2 with LLVM worked with Ubuntu 14.04LTS. However, this version becomes unsupported in April 2019. With Ubuntu 18.04LTS, there is no LLVM fortran. Clang will compile wgrib2 but you will not have the interpolation library or the fortran wgrib2api.