GBTBLS

     GBTBLS allows for specification of the GRIB decoding tables.
     The format is GBTBLS=W;N;V;C, where W is the WMO decoding table
     for parameters 1-127, N is the NCEP decoding table for 
     parameters 128-255, V is the vertical coordinate table and
     C is the originating center table.
     The defaults are 
	$GEMTBL/grid/wmogribX.tbl, 
	$GEMTBL/grid/ncepgribX.tbl,
	$GEMTBL/grid/vcrdgribX.tbl,
	$GEMTBL/grid/cntrgribX.tbl,
     where X is the version number of the GRIB message.