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Re: 20041202: Addition of .5 degree GFS to CONDUIT

Kevin,

Yes, I've just finished posting the GEMPAK 5.7.4 distribution,
and will be putting out a release announcement about that as well.

I have updated the dcgrib2 decoder to get the number of packing bits
for the JPEG2000 grids from the products and this decreases the output
file size in GEMPAK format as compared with the previous versions.

Steve Chiswell
Unidata User Support


On Thu, 2004-12-02 at 14:27, Kevin R. Tyle wrote:
> Hi Steve,
> 
> Am I correct in noting that for those of us who use GEMPAK to
> convert these files into GEMPAK grid files using dcgrib2, it is
> recommended to upgrade to GEMPAK5.7.4?  It appears that the
> packing algorithm works much more efficiently with this version
> than any prior versions.  For example, a single forecast hour,
> when degribbed, takes up about 170 MB (!) with pre-5.7.4 dcgrib2,
> but about 95 MB with 5.7.4.  (This compares with around 23 MB with
> the 1-degree GFS grib files)
> 
> --Kevin
> 
> ______________________________________________________________________
> Kevin Tyle, Systems Administrator               **********************
> Dept. of Earth & Atmospheric Sciences           address@hidden
> University at Albany, ES-235                    518-442-4578 (voice)
> 1400 Washington Avenue                          518-442-5825 (fax)
> Albany, NY 12222                                **********************
> ______________________________________________________________________
> 
> On Thu, 2 Dec 2004, Steve Chiswell wrote:
> 
> > Conduit data recipients,
> >
> > As has been mentioned previously, we will be adding the .5 degree
> > (aka grid #4) GFS grids to the CONDUIT IDD data stream on Dec 7
> > beginning with the 12Z cycle.
> >
> > You can find these files on the NWS tgftp server at:
> > ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnt/MT.gfs_CY.12/RD.xxxxxxxx/PT.grid_DF.gr2/
> >
> > The grids in these files are in GRIB2 format, and consist of forecast
> > hours 0 through 84 at 3 hour intervals (this is the period for which the
> > GFS is currently run at T254). The "DF.gr2" portion of the file
> > directory string denotes that the data is GRIB2.
> >
> > The cumulative volume of this data set will be between 900-1000 MB
> > per model cycle for an additional 3.6 to 4.0 GB per day on
> > the CONDUIT feed.
> >
> > If you are receiving files of the pattern MT.gfs. you will receive
> > these products unless you restrict your ldmd.conf request to not request
> > the DF.gr2 products (other patterns can be used as well).
> >
> > The addition of this data set means that the volume of CONDUIT IDD feed
> > will be in excess of 2 GB per hour at times during the day, meaning that
> > if your LDM queue is 2GB or smaller, then the likelihood is that you
> > will be storing less than 1 hour worth of data for relay (additionally
> > other data streams you may be receiving will also factor into this
> > size). LDM product queues on Thelma.ucar.edu and atm.geo.nsf.gov are 6GB
> > and 4GB respectively. Please be aware that the amount of data processing
> > being handled by your LDM may also be increased as with any new data
> > sets  are added to the data stream, and monitor for load and disk space
> > changes accordingly.
> >
> > Steve Chiswell
> > Unidata User Support
> >
> >
> >
> >
> >
> >
> >
> > On Thu, 2004-12-02 at 06:42, Unidata Support wrote:
> > > ------- Forwarded Message
> > >
> > > From: "Brent Gordon" <address@hidden>
> > > Date: Thu, 02 Dec 2004 07:59:18 -0500
> > > Organization: NCEP/NCO/PMB
> > > To: address@hidden, address@hidden
> > > Subject: CONDUIT model renames -- TODAY
> > >
> > > All,
> > >
> > > As advertised this past Tuesday, NCEP has now reimplemented the name
> > > change for the Eta and AVN models on CONDUIT.  These models will now be
> > > named NAM and GFS respectively.  This change will begin with the 12 UTC
> > > model cycle data today.
> > >
> > > As a reminder, we will also be adding the 0.5 degree GFS data next
> > > Tuesday (12/7).  These data will be in GRIB2 format.
> > >
> > > Brent
> > >
> > >
> > > --
> > > NOTE: All email exchanges with Unidata User Support are recorded in the
> > > Unidata inquiry tracking system and then made publicly available
> > > through the web.  If you do not want to have your interactions made
> > > available in this way, you must let us know in each email you send to us.
> > >
> > > ------- End of Forwarded Message
> >