Post processing WRF is a big task, especially when different tasks come in different times. Most of the time I can find pretty simple (and beautiful) solutions in NCL, so I decided to learn more about it. I will add more to this post when I get new codes that are useful.
NCL means NCAR Command Language, and here is the official website. It is designed to handle the climate data, so WRF is kind of natively supported. It has a package called “WRFUserARW.ncl”, which is super helpful in processing WRF results.
NCL has 3 main references, and they are great tools to start with. Here I mainly handling NetCDF files, and I am only putting some useful quick notes (or short code piece) in case I need them.
1. NetCDF variable handle
pw = wrf_user_getvar(a, "pw", -1) # Here the var is derived from a WRF output file pw!0 = "Time" # define the dimension name. Otherwise it is "ncl1" by default pw!1 = "south_north" pw!2 = "west_east" pw@units = "kg/m2 (i.e. mm)" # define the var attribute printVarSummary(pw) # to check the basic info of the variable plot = gsn_contour(pw(0,:,:,:)) # make some simple plot
2. NetCDF file handle
ncdf = addfile("test_ncl.nc","c") # get a filename fAtt = True fAtt@title = "Precipitation" # file name, displayed when opened in ncview fAtt@creation_date = systemfunc("date") # time stamp fileattdef(ncdf, fAtt) # put the above file attribute to the file
3. Calculate vars using built-in functions
 NCL official website: https://www.ncl.ucar.edu/index.shtml
 NCL documentations: https://www.ncl.ucar.edu/Document/index.shtml. This is the hub for tutorials, references and other useful materials.