McIDAS-XCD 2003 GFS MOS Addendum
Software and Instructions

19 December 2003

This is the third addendum to the May 2003 McIDAS-XCD upgrade, version 2003. The first two were dated 30 May 2003 and 13 November 2003, respectively.

On Tuesday 16 December 2003 the National Weather Service made several changes to MOS products based on GFS model output. See http://www.nws.noaa.gov/mdl/synop/changes/dec16gfs.htm for details. This addendum is necessary in order to accommodate the addition of the new Snowfall Amount (SNW) field and the addition of 145 new GFS MOS stations.

Note: Because you will need to delete or move the current day's GFS MOS MD file (step 11 below), we recommend that you install this addendum soon after 00 UTC in order to delete or move the file before it contains most of the day's data.

Required Action:

Complete the steps below to obtain and install the addendum.

1. Shut down -XCD and wait for all associated processes to exit.
2. Login to the McIDAS-XCD workstation as user mcidas.
3. Download the file DCGFSMOS to the ~mcidas/data directory. It will replace the existing version of the file. This new schema file contains the new Snowfall Amount (SNW) field and will be used to determine the internal format for future GFS MOS MD files.
4. Download the file STNDB.CORE to the ~mcidas/data directory. It will replace the existing version of the file. This new station database file has been updated with the additional GFS/ETA MOS stations. If desired, you may also copy the file to the ~mcidas/data directory on your client workstations so users can list or plot the new stations with commands MOSRPT LIST, STNLIST and STNPLOT.
5. Login to the McIDAS-XCD workstation as user oper.
6. Download the file m0gfsmos.for to the ~oper/mcidas/xcd2003/src directory. It will replace the existing version of the file. This is the GFS MOS decoder which has been modified to decode the new Snowfall Amount (SNW) data and place it into the GFS MOS MD files.
7. Rebuild -XCD so that the new GFS MOS decoder will be used.

   Type: cd ~oper/mcidas/xcd2003
   Type: . ./xcd_init
   Type: cd src
   Type: make install.bin

8. Start a McIDAS-X session under the oper account, then register the new GFS MOS MD file schema.

   Type: SCHE DCGFSMOS

9. The current limit for the number of stations allowed in the GFS MOS rapid access text file is 1400. The 145 GFS MOS stations added with this addendum puts the total over that limit. For this reason you will need to re-create your rapid access text files with a larger capacity. Run the command below from a McIDAS-X session under the oper account to delete files GFSMOS.RAP and GFSMOS.RAT and create a new GFSMOS.RAP file. The new GFSMOS.RAT file will be created as soon as the next GFS MOS message is recieved.

   Type: BILDTEXT INIT GFSMOS.RAP GFSMOS.RAT 2000 2 C4 2 12 80 GFSMOS X 48

10. Edit the file ~oper/mcidas/data/GFSMOS.CFG and change the value for NCOLS to 2000 and the value for NROWS to 42. This change increases the maximum number of GFS MOS stations that can be written to the GFS MOS MD file and increases number of forecast periods.
11. Delete or move the current day's GFS MOS MD file. You must do this because the updated GFS MOS decoder will try to write to the MD file using the updated schema, which contains the new Snowfall Amount (SNW) field. MD files that were created using the previous version of the schema do not contain this field.
12. From a McIDAS-X session running under the oper account, restart -XCD.

    Type: STARTXCD

    New GFSMOS.RAT and MD files will be generated automatically when the next GFS MOS message is recieved.

This completes the instructions. If you have any questions, send email to the McIDAS Help Desk.