VG2UKA converts VG files to ASCII files, using the UKMET browsable
ASCII format.  Currently, only high level significant weather (SWH)
and mid level significant weather (SWM) VG files may be converted.

INPUT PARAMETERS
 
    DATTIM    Date/time
    FHOUR     Forecast hour
    FXYTBL    FXY table file
    CENTER    Originating Center ID #/Sub-Center ID #/Generating Process ID #
    VGFILE    Vgfile | scale file | attribute file | filter
    UKAFIL    Intermediate input/output ASCII file
 
 

PROGRAM DESCRIPTION
 
    VG2UKA is a table-driven GEMPAK program with parameter input,
    which reads an input VG file and converts it to the UKMET
    browsable ASCII format.  (A description of this format for SWH
    and SWM data may be found in the WAFC document "Representing
    WAFS Significant Weather (SIGWX) Data in BUFR", version 2.5,
    November 2004.)  The input parameters are GEMPAK date/time,
    forecast hour, FXY table file name (chart type alias), originating
    center id, VG input file name and ASCII output file name.

    Parameters DATTIM and FXYTBL must be specified.  Default values
    for other parameters are FHOUR = 24, CENTER = 7, VGFILE =
    $SIGWX/vgfiles/YYYYMMDDHH_FF_final.vgf (from
    $GEMTBL/config/datytype.tbl, with SIGWX set by the site
    administrator) and UKAFIL = <FXYTBL>.txt.  Only the first field of
    the CENTER parameter is used; other fields are ignored.

    An SWH or SWM VG file may consist of groups of clouds, fronts, jets,
    turbulence, storm symbols and/or volcano symbols.  Tropopause
    text information and radiation symbols appear in the the file as
    ungrouped elements.  Ungrouped "JET" elements may also be used.

    See the Product Generation-BUFR help for information about
    creating the input VG file.

 
EXAMPLES
 
    1.  Convert a 24-hour forecast SWH VG file, test1.vgf, to an
	ASCII file, SIGWXHI.txt.  The originating center is NCEP.

        DATTIM  = 040527/1200
    	FHOUR   = 24
	FXYTBL  = SWH
	CENTER  = 7
	VGFILE  = test1.vgf
    	UKAFIL  = SIGWXHI.txt

    2.  Convert an 18-hour forecast SWH VG file, test2.vgf, to an
	ASCII file, SIGWXHI_18.txt.  The originating center is
        WAFC London.

      	DATTIM  = 040526/0000
        FHOUR   = 18
        FXYTBL  = SWH
        CENTER  = 93
        VGFILE  = test2.vgf
        UKAFIL  = SIGWXHI_18.txt

    3.  Using default values, convert a 24-hour forecast SWH VG
	file, $SIGWX/vgfiles/2004060718_24_final.vgf, to an ASCII
	file, SWH.txt.  The originating center is NCEP.

        DATTIM  = 040607/1800
	FHOUR   =
	FXYTBL  = SWH
	CENTER  =
	VGFILE  =
	UKAFIL  =

    4.  Convert an 18-hour forecast SWM VG file, test4.vgf, to an
        ASCII file, SIGWXMD_18.txt.

        DATTIM  = 040526/0000
        FHOUR   = 18
        FXYTBL  = SWM
        CENTER  = 7
        VGFILE  = test4.vgf
        UKAFIL  = SIGWXMD_18.txt


ERROR MESSAGES
 
    [VG2UKA  -1]    The GEMPAK date/time and/or valid hour should be input.
    [VG2UKA  -2]    Group type ... cannot be found in the group type list.
    [VG2UKA  -3]    Cannot create alias from datatyp.tbl. Check alias or inputs.
    [VG2UKA  -4]  VG file ... not found.
    [VG2UKA  -5]    Cannot mix high and mid level charts in fxytbl.
    [VG2UKA  -6]    Chart type/alias should be input.