Raw WRF Output Files

File type abbreviation: wrfout

Users needing the full detail provided in the WRF output can download the raw WRF output files for each domain. These files contain all the model levels on the native grid along with every variable in one file as output in WRF’s wrfout file format. Each wrfout file is archived independently, i.e., each time for each simulation has one file. These files use unique filenames identifying them with their associated simulations and times. See the File Naming Convention section of the documentation for details on the naming; an example is corlasso.wrfout.2019012900gefs05d4.base.M1.m0.20190129.173000.nc.

The file sizes are substantial for the innermost domains. Typical file sizes for the four domains are 623 MB, 2.8 GB, 19 GB, and 171 GB, respectively. As can be seen, working with the files for D3 and D4 can become challenging without resorting to specialized hardware and techniques, such as using Python’s Dask library to chunk the data in memory and/or parallelize tasks across multiple compute nodes. Therefore, it is recommended that users work with the subset files, described next, when possible.

The contents of the wrfout files can be seen in this example netCDF header: wrfout_hdr_D4.txt. Some variables, such as pressure and height, are stored as a pair of base and perturbation values. Other variables are located on staggered grids following an Arakawa C-grid approach. Details on the specifics of variable definitions, the grid used for the variables, and the naming of the variables can be found in the WRF User’s Guide [Wang et al., 2019].

Model output is provided every 15 minutes for domains D1, D2, and D3. The highest resolution-domain, D4, has output every five minutes.