Hi @Ming Chen , how can we calculate the rain rate (mm/hr) from accumulated RAINNC? I have a simulation for one month.RAINC and RAINNC are accumulated in wrfout files. If you have hourly wrfout, then the 24th wrfout files will contain the 24-h accumulated rainc and rainnc. You don't need to use the' sum' function.
NCL, ARWpost and Python etc all can process wrfout data and produce plots.