-- 21 September 2010 --

GRIB Version 1 files contain HPC automated 24-h snow and freezing rain analyses.

Daily files with 24-h accumulations ending at 00 and 12 UTC are found under
subdirectories named by year and month (YYYYMM).  The daily files are named
csq_YYYYMMDD.grb.

GRIB parameter number 161 corresponds to the 24-h snow accumulation.
GRIB parameter number 162 corresponds to the 24-h freezing rain accumulation.

Accumulations are in millimeters.

GRIB-1 files of zero length indicate that all grid points have missing values
for all four grids that could be in the file.  One or more GRIB messages may
be absent from the GRIB file, indicating that all points on those grids have
missing values.

GEMPAK user information:

Transfer the data to GEMPAK grid files using nagrib_nc:

    1.  Create a local parameter table file:

cat << EOF > gprm.tbl
!ID# NAME                             UNITS                GNAM         SCALE   MISSING HZREMAP DIRECTION
161 Frozen precipitation              Kg/m**2               SNOW            0  -9999.00       0         0
162 Freezing liquid prcp              Kg/m**2               ZR              0  -9999.00       0         0
EOF

    2.  Run nagrib_nc with YYYYMMDD replaced with a year-month-day date:

 GBFILE   = csq_YYYYMMDD.grb
 INDXFL   =  
 GDOUTF   = snow-zr_YYYYMMDD.grd
 PROJ     = 
 GRDAREA  =  
 KXKY     = 
 MAXGRD   = 64
 CPYFIL   = gds 
 GAREA    = grid
 OUTPUT   = T
 GBTBLS   = ;gprm.tbl
 GBDIAG   =  
 PDSEXT   = NO
 OVERWR   = NO
run
exit

For more information, contact keith.brill@noaa.gov