A method on converting text ppt data into GEMPAK surface files

Methodology:

Table file

Create GEMPAK surface file

Convert text PPT data into GEMPAK readable text

Place PPT data into GEMPAK surface file

Use sfmap to create graphics

Table file:

If text ppt data does not contain latlon for individual stations, you will need to somehow come up with the info and place it in a table file similar to that found below

If text ppt data also contains latlon pairs, read through text ppt data and create a table file with only one line per station. (Here I am limiting my search to stations west of 100 deg lat west. Also, create a base file of zero size so that the fortran program can find the file.)

Sample fortran program

Sample CSH script to run through daily text ppt data

Here's what you're reading:

 40.92   122.82   8.23 TYRC1
 40.66   122.53   7.68 SFKC1
 39.82   121.32   7.60 FRTC1
 39.90   121.20   7.56 BKLC1
 42.42   124.13   7.01 LAFO3

Here's what you're creating:

TYRC1    999999 PPT STATION                      UT US  4091 -12282     0  0
SFKC1    999999 PPT STATION                      UT US  4066 -12253     0  0
FRTC1    999999 PPT STATION                      UT US  3982 -12132     0  0
BKLC1    999999 PPT STATION                      UT US  3990 -12120     0  0
LAFO3    999999 PPT STATION                      UT US  4242 -12413     0  0

For more details on a table file, look at examples found in your GEMPAK table directory ($GEMPAKHOME/tables/stns)

GEMPAK surface file:

To create a monthly GEMPAK surface file containing 24 hour PPT totals ending at 12Z, run the GEMPAK program SFCFIL like this: (where {yy} is the year, {mm} is the month, ppt.tbl is the table file created above, etc.)

sfcfil
sfoutf={yy}{mm}ppt.gem
sfprmf=p24i
stnfil=ppt.tbl
shipfl=no
timstn=31/0
sffsrc=
run

Converting text ppt data into GEMPAK readable text:

Essentially, use a fortran program to read through your text data to reformat it into a type that the GEMPAK program SFEDIT can use to read it and put it into the GEMPAK surface file

Here's what you're reading:

 40.92   122.82   8.23 TYRC1
 40.66   122.53   7.68 SFKC1
 39.82   121.32   7.60 FRTC1
 39.90   121.20   7.56 BKLC1
 42.42   124.13   7.01 LAFO3

Here's what you're creating:

 PARM = P24I
 
    STN      YYMMDD/HHMM      P24I
    TYRC1    970101/1200      8.23
    SFKC1    970101/1200      7.68
    FRTC1    970101/1200      7.60
    BKLC1    970101/1200      7.56
    LAFO3    970101/1200      7.01

Sample fortran program

Placing ppt data into GEMPAK surface file:

Use the GEMPAK program SFEDIT to put the ppt data into the GEMPAK surface file, like this: (where {yy} is the year, {mm} is the month, and {dd} is the day)

sfedit
sfefil=test.{dd}
sffile={yy}{mm}ppt.gem
run

A CSH script can be written to perform the above three duties for a specified month. A sample script

Creating graphics:

Use the GEMPAK program SFMAP to create graphics of the ppt data

A sample script is provided that creates the following graphic:

SFMAP can be used in a variety of ways to create graphics of your ppt data in the style that you want. Consult your GEMPAK User's Guide for more information or email me.

Last updated 06 November 1997