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I had a question about the GFS files on your ancillary ftp site. Your documentation (ftp://ftp.ssec.wisc.edu/pub/eosdb/ancil ... ILLARY.txt) indicates that they are being pulled from ftp://ftp.ncep.noaa.gov/pub/data/nccf/c ... 06,12,18}/ and it looks like the NCEP grib2s are also being reformatted into grib1 on your end. However there are different types of gfs files in that NCEP location. Can you please let me know which NCEP GFS file type is being used? It seems it could be the gfs.t{00,06,12,18}z.pgrb2.1p00.f0{03,06,09,12} files. Can you confirm?
Thanks in advance.
-- Vanu

Hello,

All of the files posted on the IMAPP ancillary data archive site are used to support one or more IMAPP software packages. Can you be more specific? What software are you trying to execute?

Kathy

I am executing IMAPP and I understand that all the required ancillaries are already available on your ftp site. Also, I have no problems executing IMAPP.

I am just interested to know about the upstream source of the GFS files posted on your site. The documentation on your ftp site suggests that the upstream source for GFS is the NOAA NCEP site ( ftp://ftp.ncep.noaa.gov/pub/data/nccf/c ... 0,06,12,18}. But the NCEP site has various types of GFS files. I would like to know which GFS type is being made available on your ftp site? I think it is the gfs.t{00,06,12,18}z.pgrb2.1p00.f0{03,06,09,12} file variety on the NCEP site which you are then renaming/reformatting for IMAPP compliance. Can you confirm?

Thanks,
-- Vanu

Hi Vanu,

Yes, you are correct. The files we pull are located:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/c ... DD${RUN_HR}

with the file format:

gfs.t${RUN_HR}z.pgrb2.1p00.anl
gfs.t${RUN_HR}z.pgrb2.1p00.anl.idx

and

gfs.t${RUN_HR}z.pgrb2.1p00.f0{03,06,09,12}?
gfs.t${RUN_HR}z.pgrb2.1p00.f00{03,06,09,12}.idx

where ${RUN_HOUR} is 00, 06, 12, 18, for the forecast hours of 03, 06, 09, 12.

These files from NCEP are in grib2 format. We internally convert these files to grib1 and rename them before posting them to our ftp site.

I apologize for the error in our documentation on the ftp site. We will review and update the documentation.

Thanks,

~Jess

This helps a lot. Thanks for confirming that the gfs.t${RUN_HR}z.pgrb2.1p00.f0{03,06,09,12} on NCEP is being renamed/reformatted into gfs.t${RUN_HR}.yymmdd.pgrbf{03,06,09,12} on your site. But I am now unsure of what happens to the gfs.t${RUN_HR}z.pgrb2.1p00.anl file type on NCEP when it gets to your site? How is that renamed on your site? Also, how do you use the .idx files?
-- Vanu