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What gfs files should I use for my run?

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g_vijayan

Member
Hi,
I am a little confused regarding the gfs files I need to provide for my WRF run. I need to integrate the model for 24 hours starting from 2018-09-20_00UTC. But I have a six hour spinup period before that. Now, will I have to use gfs files
gfs.0p25.2018091918.f(000-030).grib2
or
gfs.0p25.2018091918.f(000-005).grib2 and gfs.0p25.2018092000.f(000-024).grib2
or
is it something else?
Please help me out.
 
Hi,
If you understand the meaning of the gfs file names. you will know what files to use. Suppose we have a file named "gfs.0p25.yyyymmhh.fnnn,gribs"
yyyymmddhh indicates the initial time of the GFS, nnn indicates the forecast hours.
Therefore, when you see a GFS file named gfs.0p25.2018091918.f000.grib2, it is the GFS analysis data at 2018091800. The file gfs.0p25.2018091918.f030.grib2 means 30-hour forecast of GFS initialized at 2018091800
Hope this is helpful for you to choose what files to use.
 
Ming Chen said:
Hi,
If you understand the meaning of the gfs file names. you will know what files to use. Suppose we have a file named "gfs.0p25.yyyymmhh.fnnn,gribs"
yyyymmddhh indicates the initial time of the GFS, nnn indicates the forecast hours.
Therefore, when you see a GFS file named gfs.0p25.2018091918.f000.grib2, it is the GFS analysis data at 2018091800. The file gfs.0p25.2018091918.f030.grib2 means 30-hour forecast of GFS initialized at 2018091800
Hope this is helpful for you to choose what files to use.

Hi Ming,
Thankyou for the reply!
I did understand the meaning of the gfs file names. But I am still unclear on what files I need to use.
I believe both gfs.0p25.2018091918.f(000-030).grib2
and
gfs.0p25.2018091918.f(000-005).grib2 and gfs.0p25.2018092000.f(000-024).grib2
options will be valid as inputs in my case, but I'm not sure which one will be the right one to use.

I've found on the forums that, for a 24 hour run, people generally use files from 0 hour forecast to 24 hour forecast. Is that the right thing to do?

And if that is the case, should I treat my spinup period and the model integration post spinup as two separate runs and start both the spinup run and post spinup integration with 0 hour forecast files respectively? (i.e, in my case, should I use gfs.0p25.2018091918.f(000-005).grib2 and gfs.0p25.2018092000.f(000-024).grib2 )
Please help me out.
 
I have a six hour spinup period from 2018-09-19_18 UTC to 2018-09-20_00 UTC. Then, I need to integrate the model for 24 hours upto 2018-09-21_00UTC.
 
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