[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

20031114: GRIB2?

Rob,
The ETA files on the FTP server use JPEG2000 compression in GRIB2 which
is not part of the GRIB2 encoder/decoder in our release at this time.

You can download software for grib2 and for grib2 to grib1 here:
http://www.nco.ncep.noaa.gov/pmb/codes/GRIB2/

Steve Chiswell


On Fri, 2003-11-14 at 12:47, Rob Dale wrote:
> NCEP is now producing the full 3D Eta datasets at native 12km on their FTP
> site, but they are in grib2 format... Is there anything in GEMPAK that will
> convert these? I tried dcgrib2 but got:
> 
> bulletin too long 79134 > 0
> Grid id 53 not in grdnav.tbl
> 
> ===
> 3. 12 km Eta in GRIB2
> 
> The WSI and Meteorlogix has made a request (through TOC) that NCEP make
> available the full 3-D data sets from the Eta at its native 12 km
> resolution. Due to the size of these data in GRIB1 (>100 MB each) we would
> like to make these available in GRIB2. Using the JPEG2000 compression
> technique in the NCEP GRIB2 code, we are able to compress these data down to
> 20 MB per file. These data are available four times per day in 3 hour
> increments out to 84 hours for a total of 29 files. This makes the total
> size of these data 600 MB per cycle and 2.4 GB per day. Since the JPEG2000
> compression algorithm has not yet been officially sanctioned by the WMO, we
> would like these data to be placed in the ST.opnt filesystem. This is the
> same place we are currently placing the GFS data in GRIB2. The directory and
> filename structures are as follows:
> 
> /SL.us008001/ST.opnt/MT.eta_CY.{HH}/RD.{YYYYMMDD}/PT.grid_DF.gr2
> 
> (where HH = 00, 06, 12, 18)
> 
> fh.{hhhh}_tl.press_gr.awp218
>