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[GEMPAK #ALF-313013]: Some P06M ensemble fields missing

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  • Subject: [GEMPAK #ALF-313013]: Some P06M ensemble fields missing
  • Date: Tue, 03 Oct 2006 15:41:20 -0600
Art,

The "end time" specified in the data (PDT 4.11) is being set to the initial 
time in the data
for those products after 252 hours, so you are seeing the data being stored as
F000 grids, and then the accumulation time which should be 6 hours before the 
end time
becomes negative numbers, eg P-378M at F000 rather than P06M at F384.

I've looked at the GRIB2 documentaton as well as the code, and the code seems to
match the documentation. The change in the data at 252 hours is that the 
encoded forecast time 
changes from unit hours to 6 hours at that point. Eg,  the 378 hour start time 
is encoded as 63
with a code table indicator meaning 6 hour units. All that code matches the 
documentation.

I have sent a note to NCEP to try to see what's up.

Steve Chiswell
Unidata User Support


> Hi...
> 
> We're looking at the new GRIB2 ensemble data and notice that the P06M
> fields are available from 0-252 hours, but are not available after that.
> In addition, we notice some odd-looking fields named P-252 -> P-384 in the
> zero-hour forecast files.  Is there some sort of bug/error in the data or
> decoding process, or some new "feature" we're unaware of?
> 
> Thanks.
> 
> Art
> 
> Arthur A. Person
> Research Assistant, System Administrator
> Penn State Department of Meteorology
> email:  address@hidden, phone:  814-863-1563
> 
> 


Ticket Details
===================
Ticket ID: ALF-313013
Department: Support GEMPAK
Priority: Normal
Status: Closed