NCEP ENSEMBLE GRIB DATA INFO


 
 

Information on this page:

Other relevant information:

  • Fast Downloading of GRIB Files (partial http transfers)

  • Updated documentation for ensemble data information


  • Getting NCEP Ensemble data via anonymous ftp

    NCEP Ensemble data are currently available via anonymous ftp on 3 different servers:

    Typically, the NCEP ftp server will have a few recent days worth of data on-line, while the NWS server will only have the data for the current day. The data are grouped together according to variable. For example, the file  enspost.T00Z.z500 will contain all 12 ensemble perturbation forecasts for 500 mb height for 00z for the day given by the directory name. The following variables are available in this file: For each variable, 1 file is written for the 12 00z perturbations and 1 file is written for the 5 12z perturbations. In each file and for each perturbation, data are included every 12 hours from valid time = 00h to 384h. GRIB index files are also included on these servers in the same directory as the GRIB data files, and are identified by the "i" after the parameter identifier in the file name (e.g.,  enspost.T00Z.z500i ).

    In addition, a file containing probabilistic quantitative precipitation forecasts (PQPF), derived from the ensemble, is also available.

    FTP Access to NCEP GRIB decoding software

    You can find NCEP GRIB decoding software at the following location:

    The NCEP ftp server:

    ftp://ftp.ncep.noaa.gov/pub/nws/nmc/codes/

    Take a look at the README file. Read that and then cd to the subdirectories to download the software.
     

    *** You can find help using NCEP's GRIB decoding software by clicking here ***

    Understanding the Ensemble GRIB PDS extension

    NCO maintains a web document describing the format of the NCEP GRIB section for ensembles:
    NCEP USE OF THE EXTENDED GRIB PDS SECTION FOR DESCRIBING ENSEMBLE OUTPUT

    Go back to NCEP Ensemble Home Page 
    Go back to NCEP Ensemble Implementation News