NCEP/EMC 4KM Gridded Data (GRIB) Stage IV Data

The Stage IV analysis is based on the multi-sensor hourly/6-hourly 'Stage III' analyses (on local 4km polar-stereographic grids) produced by the 12 River Forecast Centers (RFCs) in CONUS. NCEP mosaics the Stage III into a national product (the Stage IV). Hourly, 6-hourly and 24-hourly (accumulated from the 6-hourly) analyses are available. The Stage IV differs from the NCEP Stage II chiefly in that the NCEP Stage II contains no manual quality control (QC), while the Stage IV benefits from manual QC performed on the Stage III data at the RFCs. As of April 2017 this data includes Alaska and Puerto Rico stations. As of 20 July 2020, data file formats changed from GRIB1 to GRIB2, with similar name changes (e.g., *.grb2). Starting on 20 July 2020, the GRIB1 files may not have complete data. Please refer to the GRIB2 files instead.

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Questions? Email Resource Support Contact:

  • EOL Data Support
    datahelp@eol.ucar.edu

Temporal Range

  • Begin:  2001-12-31T12:00:01Z
    End:  2025-08-31T23:00:00Z

Keywords

Resource Type dataset
Temporal Range Begin 2001-12-31T12:00:01Z
Temporal Range End 2025-08-31T23:00:00Z
Temporal Resolution N/A
Bounding Box North Lat 71.41300
Bounding Box South Lat 17.85300
Bounding Box West Long -176.83600
Bounding Box East Long -65.54400
Spatial Representation grid
Spatial Resolution N/A
Related Links

Documentation #1 : katz_missing_data.txt

Documentation #2 : katz_stageIV_readme.txt
Additional Information N/A
Resource Format Unix Compressed (.Z) Gridded Binary (GRIB) Format (application/x-compress)
GNU Zip Compressed (.gz) Gridded Binary (GRIB) Format (application/x-gzip)
GNU Zip (.gz) Format (application/x-gzip)
GRIB-2: Gridded Binary Edition 2 (GRIB)
Standardized Resource Format Archive
GRIB
Asset Size 25909 MB
Legal Constraints

none
Access Constraints none
Software Implementation Language N/A

Resource Support Name EOL Data Support
Resource Support Email datahelp@eol.ucar.edu
Resource Support Organization N/A
Distributor N/A
Metadata Contact Name EOL Data Support
Metadata Contact Email datahelp@eol.ucar.edu
Metadata Contact Organization N/A

Author Jun Du
Publisher N/A
Publication Date 2011-08-11T16:06:08
Digital Object Identifier (DOI) https://doi.org/10.5065/D6PG1QDD
Alternate Identifier 21.093
Resource Version 1.0
Topic Category climatologyMeteorologyAtmosphere
Progress completed
Metadata Date 2025-10-07T21:45:06Z
Metadata Record Identifier edu.ucar.eol::21.093
Metadata Language eng; USA
Suggested Citation Jun Du. (2011). NCEP/EMC 4KM Gridded Data (GRIB) Stage IV Data. 1.0. https://doi.org/10.5065/D6PG1QDD. Accessed 24 October 2025.

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