The -ftime option nominally prints the Forecast TIME.
It will print the forecast time, accumulation period, etc.
There are two types of simple time stamps, simple ones like a
The next step up is a single statistical processing which involves a statistical operator
(such as average, accumulation, maximum) and one or more fields. Examples are
- analysis, anl
- 12 hour forecast, 12 hr fcst
- average (00Z analysis, 06Z analysis, 12Z analysis, 18Z analysis), 4@6 hr ave(anl)
- average (analysis, 6 hr fcst, 12 hr fcst, 18 hr fcst), 0-18 hr ave(fcst,dt=6 hr)
- average (every forecast time step from 6 to 12 hours), 6-12 hour ave fcst
The next step is where you have multiple statistical processing steps. For example, you have
the precipitation over 6 hour which involves a single statistical processing step. Now you take the monthly
mean of that. That involves two statistical processing steps. Now if you take make a 30-year
climatology, then you need 3 statistical processing steps.
It was noted that the old ftime had problems with the more complicated time stamps and
ftime2 was developed to be an eventual replacement. Similarily set_ftime2 was developed
to replace the old set_ftime/set_ave options.
$ wgrib2 grib2.polar -ftime
1.1:0:24 hour fcst
1.2:0:24 hour fcst
See also: -vt