How to Ingest and Display NCEP Model Output into GEMPAK

How to Ingest and Display NCEP Model Output into GEMPAK

  • GEMPAK can display both GRIB1 and GRIB2 model output
  • dcgrib2 to translate the GRIB1 and GRIB2 files to .gem files for use in GEMPAK.
  • GEMPAK can view WRF output (originally in netCDF) by converting the netCDF to GRIB, to see more on this process, visit WRF netCDF to GEMPAK

    How to set up your GEMPAK LDM configuration files

  • The GEMPAK distribution includes a template script that will have the most current actions included. To see more information regarding this process vistit the GEMPAK documentation about this topic.
  • The information below is only an example of how the ldmd.conf and pqact.conf files may look. Your paths and actions may differ, but the information below should give a general idea on the process as well as descriptions and explanations of some of the terms.

    ldmd.conf

  • How to request NCEP model data via the LDM
  • ldmd.conf example entry:

    ########################################
    # Request Entries
    ########################################
    #
    # LDM servers request data from Data Sources
    #
    # (request) (feedset) (pattern) (hostname pattern)

    request      HDS      ".*"     idd.unidata.ucar.edu
    [sample host pattern, yours may differ]

  • For more information regarding the HDS feed and other feedtypes, please visit: Feedtypes

    pqact.conf

  • How to "act" on the data once it is on disk in the LDM queue
  • Reminder..ALL spaces in the pqact.conf file need to be (tabs)!
  • pqact.conf example entries:

    # The following NAM entries can be used to select individual NAM
    # grids to decode!!!
    #
    # NAM #211 80km grid CONUS
    HDS (/mNAM|/mNMM).*#211
    PIPE  decoders/dcgrib2 -d data/gempak/logs/dcgrib2_NAM211.log
    -e GEMTBL=/home/gempak/NAWIPS/gempak/tables
    #
    # NAM #212 40km grid CONUS
    HDS|CONDUIT (/mNAM|/mNMM|MT.nam|prod/nam).*#212
    PIPE  decoders/dcgrib2 -d data/gempak/logs/dcgrib2_NAM212.log
    -e GEMTBL=/home/gempak/NAWIPS/gempak/tables


    GEMPAK Home Page

    If you have additional questions they should be directed to:
    support-gempak@unidata.ucar.edu