wgrib2: -set_ftime
Introduction
The wgrib2 inventory has a fragment that looks like
:d=2014122500:12 hour fcst:vt=2014122512
d=2014122500 is the Reference time, usually the analysis or start of the forecast time.
12 hour fcst is the "ftime", the time is 12 hours after the reference time
vt=2014122512 is the verification time (ref time + 12 hours)
Wgrib2 has options to change the reference time (-set_time) and to set the ftime.
The -set_ftime v2 (introduced with wgrib2 v2.0.7) is easier to use and will
change the Product Definition Templates as needed. For compatibility, -set_ftime v1
is still available on wgrib2 v2.0.7+. However, -set_ave and -set_ftime v1
should not be used as they will be eventually removed.
To change the ftime, you add the option -set_ftime FTIME. What are the allowed formats
of FTIME? The formats are the same as ftimes from a wgrib2 inventory.
Original: :d=2014113018:6 hour fcst:
options: -set_date 2014122500 -set_ftime "12 hour fcst"
New: :d=2014122500:12 hour fcst:
Original: :d=2014113018:6 hour fcst:
options: -set_date 2014122500 -set_ftime "0-6 hour ave fcst"
New: :d=2014122500:0-6 hour ave fcst:
Original: :d=2014113018:6 hour fcst:
options: -set_date 2014122500 -set_ftime "124@6 hour ave(0-6 hour ave fcst),missing=0"
New: :d=2014122500:124@6 hour ave(0-6 hour ave fcst),missing=0:
After changing the time stamp, you can save the file with -grib NEW.grb
With wgrib2 v2.0.6 or earlier, you have to use -set_ave and -set_ftime (v1).
Only a subset of PDTs were supported by -set_ave and -set_ftime (v1).
See also:
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