[Wrf-users] Trying to ungrib NAM "conduit" data

[Don Morton]

I'm afraid I'm a little vague on all this, but I've  been using
NAM Grid 216 (Alaska 45km) data for operational runs, and
one source of this data is

http://motherlode.ucar.edu:8080/thredds/catalog/model/NCEP/
                                  NAM/Alaska_45km/conduit/catalog.html

This particular dataset has all the forecast hours jammed into a single,
huge file.  "Apparently" (this is where I'm a little vague) the records
in this file are not necessarily ordered by date.  With WRFSI we would
put the following statement in grib_prep.nl

ORDERED_BY_DATE = FALSE

without this statement, the degribbing would typically create intermediate
files that weren't complete.  With the statement, all would be groovy.

We're now trying this sort of thing with WPS, but according to the documentation
for ungrib.exe, there are only two valid variables for the UNGRIB section of
namelist.wps, and neither of them deal with this issue.

Does anybody know of a way to make ungrib.exe behave the way we were
able to make grib_prep behave, reading this NAM data that apparently isn't
always ordered by date?

Thanks,

Don

-- 
Don Morton
Department of Computer Science
The University of Montana - Missoula
http://www.cs.umt.edu/~morton/