The example on this page illustrates how one can set up pregrid.csh to process a GRIB dataset. The data we use in the example are downloadable in real-time from NCEP's ftp site:

ftp://ftp.ncep.noaa.gov/pub/data1/eta/erl.yymmdd/{eta.T00Z.AWIP3D*.tm00, eta.T12Z.AWIP3D*.tm00}

where yy is two-digit year, mm two-digit month, and dd two-digit day.

If you have compiled REGRID, there is no need to recompile.

cd to REGRID/pregrid, and edit pregrid.csh:

- set DataDir to be the directory where the ETA AWIP data are

- set SRC3D = GRIB

- set SRCSST, SRCSNOW, and optionally SRCSOIL = $SRC3D if you are using the same data for 3-D meteorological fields, SST and snow.

- set the beginning and ending times for data processing, and set data interval. ETA AWIP data come in at 3 hour interval, so you may set INTERVAL = 10800 (seconds)

- For GRIB data, you also need to select the correct Vtables. For this data set, we set:

    set VT3D = ( grib.misc/Vtable.AWIP3D )
   set VTSST = ( grib.misc/Vtable.AWIPSST )
   set VTSNOW = ( grib.misc/Vtable.AWIPSNOW )
   set VTSOIL = ( grib.misc/Vtable.AWIPSOIL )

We have provided Vtables for several GRIB datasets: Eta AWIP, Eta 212, NCEP/NCAR Reanalysis, ECMWF's TOGA, and ECMWF's Reanalysis. You can also create your own Vtables, or edit the existing ones to meet your need.

Click here to see an editted pregrid.csh for the above dataset.

Type the following to run pregrid:

pregrid.csh >& log &

If you are successful, you should find these additional files generated in the pregrid directory:

-rw-r--r--   1 mesouser users    19129600 May 16 19:35 FILE:2001-05-16_12
-rw-r--r--   1 mesouser users    19129600 May 16 19:35 FILE:2001-05-16_15
-rw-r--r--   1 mesouser users    19129600 May 16 19:35 FILE:2001-05-16_18
-rw-r--r--   1 mesouser users    19129600 May 16 19:35 FILE:2001-05-16_21
-rw-r--r--   1 mesouser users    19129600 May 16 19:36 FILE:2001-05-17_00
-rw-r--r--   1 mesouser users       95648 May 16 19:36 SNOW_FILE:2001-05-16_12
-rw-r--r--   1 mesouser users       95648 May 16 19:36 SNOW_FILE:2001-05-16_15
-rw-r--r--   1 mesouser users       95648 May 16 19:36 SNOW_FILE:2001-05-16_18
-rw-r--r--   1 mesouser users       95648 May 16 19:36 SNOW_FILE:2001-05-16_21
-rw-r--r--   1 mesouser users       95648 May 16 19:36 SNOW_FILE:2001-05-17_00
-rw-r--r--   1 mesouser users     1052128 May 16 19:36 SOIL_FILE:2001-05-16_12
-rw-r--r--   1 mesouser users     1052128 May 16 19:36 SOIL_FILE:2001-05-16_15
-rw-r--r--   1 mesouser users     1052128 May 16 19:36 SOIL_FILE:2001-05-16_18
-rw-r--r--   1 mesouser users     1052128 May 16 19:36 SOIL_FILE:2001-05-16_21
-rw-r--r--   1 mesouser users     1052128 May 16 19:36 SOIL_FILE:2001-05-17_00
-rw-r--r--   1 mesouser users       95648 May 16 19:36 SST_FILE:2001-05-16_12
-rw-r--r--   1 mesouser users       95648 May 16 19:36 SST_FILE:2001-05-16_15
-rw-r--r--   1 mesouser users       95648 May 16 19:36 SST_FILE:2001-05-16_18
-rw-r--r--   1 mesouser users       95648 May 16 19:36 SST_FILE:2001-05-16_21
-rw-r--r--   1 mesouser users       95648 May 16 19:36 SST_FILE:2001-05-17_00
 

If you didn't choose SOIL table, you won't be getting SOIL_FILE*. But you must obtain SST and SNOW files so that regridder can be run successfully.

This example only shows data obtained over a 12-h interval. But you really should run pregrid for at least 24 h period for the reason described on the REGRID page.

If you have run REGRID successfully, move to the next program: RAWINS or LITTLE_R.

If you have questions, ask mesouser.