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Re: Extended GFS 0.5 degree data

Steve, et al,

One other thing I noticed, it takes a LOT more CPU power and 
disk i/o bandwidth to decode the 0.5 deg GFS files in real time
than it does to decode the 1 deg GFS. In fact, f5.aos.wisc.edu
(dual PIII 1 Ghz, 3 Gb RAM, data being written to a 3 disk scsi RAID0
filesystem, 4 Gb ldm queue) was not able to keep up decoding the 
0.5 GRIB2 files into gempak format. The gempak files were truncated, 
as if the GRIB2 data were being overwritten in the queue before
the decoder had gotten to them.

I've currently got the GRIB2 -> gempak stuff running on another machine
(dual athlon MP2600+, 2 Gb ram, SATA RAID1 filesystem, 4 Gb ldm queue)
and it is able to keep up as far as I can tell, with the exception
from my prior email that the raw GRIB2 files from conduit do not match
up size-wise with the files if I ftp them from tgftp, and the CONDUIT
files give wgrib2 errors, and will not work with the WRF.

Pete

In a previous message to me, you wrote: 

 >
 >CONDUIT data users,
 >
 >We would like to increase the 0.5 degree (grid #4) GFS availability to
 >the CONDUIT data stream as discussed at the working group meeting in
 >January:
 >http://www.unidata.ucar.edu/projects/CONDUIT/Unidata_CONDUIT_Status_and_Imple
  >mentation_Update.pdf
 >
 >Currently, the CONDUIT feed provides F000 through F084 fields for the
 >GFS at the half degree resolution in GRIB2 format. We now have access to
 >the grids through F180 (an additional 1.2GB of data per model cycle)
 >and plan to add this to the data stream.
 >
 >The addition of these files will involve a change in source file names
 >of the existing and additional data files from the NWS ftp server file
 >naming convention: 
 >ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnt/MT.gfs_CY.HH/RD.YYYYMMDD/PT.grid
  >_DF.gr2/fh.FFFF_tl.press_gr.0p5deg
 >to the NCEP ftp server naming convention:
 >ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/gfs/prod/gfs.YYYYMMDD/gfs.tHHz.p
  >grb2fFFF
 >
 >If you are currently using the 0.5 degree GFS products and the change of
 >file naming would cause problems for your use of the data, please
 >contact address@hidden as soon as possible.
 >Eventually, we would like to remove the legacy 1.0 degree GRIB1 format
 >(grid #3) products currently being sent in CONDUIT for the same
 >F000-F180 time period to allow for additional new data sets. We
 >encourage all users to transition to GRIB2 along with the NWS
 >announced changes so that new data sets can be utilized to their
 >fullest extent.
 >
 >Steve Chiswell
 >Unidata User Support
 >
 >=============================================================================
  >==
 >To unsubscribe c2, visit:
 >http://www.unidata.ucar.edu/mailing-list-delete-form.html
 >=============================================================================
  >==
 >


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^ Systems Programmer               V Madison,         WI     53706    ^
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