It should be mentioned that the NCEP Stage IV archived data is in GRIB1 format and it cannot be ingested into the WRFDA directly. A tool “precip_converter” is provided to reformat GRIB1 observations into the WRFDA-readable ASCII format. It can be downloaded from the WRFDA users page at http://www2.mmm.ucar.edu/wrf/users/wrfda/download/precip_converter.tar.gz. The NCEP GRIB libraries, w3 and g2 are required to compile the precip_converter utility. These libraries are available for download from NCEP at http://www.nco.ncep.noaa.gov/pmb/codes/GRIB2/. The output file to the precip_converter utility is named in the format ob.rain.yyyymmddhh.xxh; The 'yyyymmddhh' in the file name is the ending hour of the accumulation period, and 'xx' (=01,06 or 24) is the accumulating time period.