(1) Make sure your build environment has the following variables defined: export WRFIO_NCD_LARGE_FILE_SUPPORT=1 export WRF_DFI_RADAR=1 (2) Go into hrrr_wrf.fd/WRFV3.4.2 (3) Type "./clean -aa" (4) Type "./clean -a" (5) Type "./configure" (6) Enter option "15" and then opti "1" and that will create a configure.wrf file with all the compilation flags (7) Type "./compile em_real >& compile.log.YYYYMMDDHH" and that will build WRF (will take 10-15 min) (8) The WRF executables will be located in WRFV3.4.2/main/real.exe and WRFV3.4.2/main/wrf.exe (9) Rename the old executables in the exec directory by typing "mv /nwprod/hrrr.v1.0.0/exec/hrrr_real /nwprod/hrrr.v1.0.0/exec/hrrr_real.YYYYMMDDHH" and "mv /nwprod/hrrr.v1.0.0/exec/hrrr_wrfarw /nwprod/hrrr.v1.0.0/exec/hrrr_wrfarw.YYYYMMDDHH" (10) Copy and rename the new executables into the exec directory by typing "cp main/real.exe /nwprod/hrrr.v1.0.0/exec/hrrr_real" and "cp main/wrf.exe /nwprod/hrrr.v1.0.0/exec/hrrr_wrfarw"