GEMPAK supports gdattim forecast times expressed as:
So you can use forecasts to a resolution of 1 minute such as can be done
with wrf_post's grib output decoded into GEMPAK format with dcgrib2
(though the question has been posed previously about how to represent
thunderstorm simulations with 30 second output which can't be
represented). If your mm5to gem can
generate the time string, GEMPAK can handle it.
In answer to your #2 below,
You can use the inline qualifiers to set the GRDNAM to a time
other than GDATTIM in the GDDIAG program. See example
#3 in the GDDIAG online help as an example.
Unidata User Support
On Mon, 2007-08-13 at 17:06 -0400, David Novak wrote:
1) Has anyone converted MM5 output to 15 min GEMPAK output? I'm familiar
with the MM5TOGEM program floating around, but it seems to only do
hourly conversions. I didn't want to reinvent the wheel.
2) Is there a way to write the times of variables in a GEMPAK file to a
different time? For instance, I want 021225/000F011 to be written as
021225/0000F01130 (which should be a 11 h and 30 min forecast). GDDIAG
and GDMOD both need gddatim set to the original time.