I'm trying to use GEMPAK to split up the run-total accumulated precip
values supplied in the public GEM (Canadian) data into 3-hourly chunks.
I used dcgrib to create GEMPAK grid files of "P45M" and "P48M" from
the +f045 and +f048 grib files, then used GDDIAG to create a new GEMPAK
grid file, subtracting the two fields, and calling the new grid "P03M"
I get the following output from GDINFO (run on the new P03M grid):
NUM TIME1 TIME2 LEVL1 LEVL2 VCORD PARM
1 080307/1200F048 080307/1200F045 0 NONE P03M
Note that this is run with GFUNC=P03M, GLEVEL=0, GVCORD=NONE, GDATTIM=ALL.
However, I can't get this data to display using GDCNTR or GDPLOT3. They
all complain about the GDATTIM value. "ALL" is not accepted as a proper
value in GDCNTR or GDPLOT3, and listing "last" or even "80307/1200F048"
doesn't work either.
Note that using GDDATTIM=all is the only way to get GDINFO to list the
Any thoughts on what I might be doing wrong?