On-line Internet Anonymous FTP Access

The alternative on-line realtime access described next is intended to support ONLY acquistions of small snapshots of data for the purpose of learning data formats, data contents, and data suitability. The on-line file server does not have the communication bandwidth to support continuous daily acquistion of large data sets by multiple users.

Many GCIP users may be interested only in near-surface fields. Hence the model output file structure has been designed to provide near-surface fields in smaller compact files separate from the much larger files of 3-D atmospheric fields. Routine FTP access of the smaller "surface" files MAY be feasible.

The retention period for the on-line files is only 24 hours.

To access meso EDAS/ETA output files via anonymous ftp:

     Server address:     ftpprd.ncep.noaa.gov
     Anonymous ID:       "anonymous"
     Password:           your personal Internet E-mail address
Once logged-on, you will be in the root "/" directory. Next change directory ("cd") to

 /pub/gcp/eta/T00Z/awip212     (output from 00Z ETA forecast cycle) 

 /pub/gcp/eta/T12Z/awip212     (output from 12Z ETA forecast cycle)
 /pub/gcp/edas/T00Z/awip212    (output from 00Z EDAS assimilation cycle)

 /pub/gcp/edas/T12Z/awip212    (output from 12Z EDAS assimilation cycle)
The awip212 directories contain the 2D/3D gridded ETA/EDAS output files with the following prefix in their names:

        AWIP3D...       (3-D atmospheric fields)
        AWIPSF...       (2-D near surface fields)
for detailed descriptions of the contents of these files, go to Contents of the 2D/3D gridded fields. The 2D/3D gridded files are written or "packed" in an international WMO format known as GRIB. For documentation of the GRIB format and for unpacking software, go to GRIB unpacking.

The molts directories contain hourly 'profiles' output at selected horizontal locations. For more information about these files, go to The hourly station profiles output (molts). These files are packed in the WMO BUFR (Binary Universal Form for the Representation of meteorological data) format. For documentation of the BUFR format and for unpacking software, go to BUFR unpacking

For Those Who Need Reliable Day-to-day Access to Eta Output
Last updated: 29 Nov 2001

ftpprd.ncep.noaa.gov is not an operational server, and as such it is not supported on a 24x7 basis - a break in connection, or anything goes awry in the non-operational pipeline, might cause a failure of data update. So the above is good for getting a snapshot of the Eta/EDAS output supported by the NCEP/EMC ETA/GAPP effort, but if you need reliable day-to-day access to Eta output, you might want to go to the official NWS/OSO (Office of Systems Operation) website at ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl. Under which, go to subdirectories MT.eta_CY.## (##=00 or 12, for the 00Z and 12Z cycles) for forecast and hour 0 analysis. Once you are in MT.eta_CY.##, go to subdirectory RD.yyyymmdd/PT.grid_DF.gr1. The forecast/0-h analysis files are in fh.hour_tl.press_gr.awip3d (where hour=0000,0003,0006, etc.) These are files on grid 212 that contain fields in both the 'AWIP3D' and 'AWIPSF' files in the ETA/GAPP site (the original ETA output is 'AWIP3D'. We split up the original 'AWIP3D' into two parts, and call the resulting files 'AWIP3D' and 'AWIPSF', so that GAPP users who need only surface-related files would be able to get data in smaller volumes, to save bandwidth.

The OSO site does not contain EDAS data, only the forecast and the Hour 0 analysis.

For Further Information about These Data
The above information about the data on the OSO server is for your convenience only. The intricacy of the file structure on the OSO server makes it impractical for EMC or the ETA/GAPP Project Team to answer questions about them. If you have further questions about the OSO server or the data on them, please consult

The NWS/OSO (NWS Data Management) website
their Cross-reference of directory/file structures (before and after 26 Nov 2001)
Or email nws.dm@noaa.gov