Basics for Running the Model

Below is a depiction of the program flow during a typical model run.

WPS

geogrid.exe creates terrestrial data (static).
ungrib.exe unpacks GRIB meteorological data and packs it into an intermediate file format.
metgrid.exe interpolates the meteorological data horizontally onto your model domain.
     Output from metgrid.exe is used as input to WRF.

WRF ARW

real.exe vertically interpolates the data onto the model coordinates.
wrf.exe generates the model forecast.

Detailed information on all components are available in the User's Guide. Peruse Chapter 3 for details on WPS, and Chapter 5 for details on WRF ARW.

Frequently Asked Questions Should I run GEOGRID or UNGRIB first? It does not matter in which order these two programs are run, as they are independent from each other. Additionally, re-running one does not require that you re-run the other. Depending on your case setup you may choose to run one or the other first.

Before we run a specific case, let's first looks at some details regarding each of the individual components.

Basics - GEOGRID