GFS Grid Labeling Addendum
Software and Instructions

30 May 2003

This is the first addendum to the May 2003 McIDAS-XCD upgrade, version 2003.

Between April 2002 and April 2003 the National Weather Service merged the MRF and AVN forecast models into what is now called the GFS (Global Forecast System). An official notice can be found at http://www.nws.noaa.gov/om/notifications/tin03-07gfs.txt.

In order to maintain consistency with the NWS, we have made this McIDAS-XCD software addendum available. The addendum changes the value of the SRC field in real-time GFS (formerly AVN/MRF) grids from "AVN" or "MRF" to "GFS". The software changes were not included in the -XCD 2003 upgrade because user actions are required prior to implementation of the SRC field change. Thus, you can install the 2003 upgrade, then install these changes at a later time when you can give sufficient warning to your users.

Note: You should give your users several days notice before installing this addendum. The notice should inform users that if they have scripts, BATCH files, F-Key menus, McBASI programs or SKE entries with GRD* commands (GRDCOPY, GRDDISP, GRDIMG, GRDINFO and GRDLIST) that contain SRC=AVN or SRC=MRF, they must be changed to include GFS. The best way to do it is to add GFS without removing AVN or MRF (e.g., change SRC=AVN to SRC=AVN GFS). We recommend that you tell your users to make these changes as soon as possible, as it will allow their GRD* commands to work with both the current and future SRC field values. Please note that in McIDAS-X 2003, all five GRD* commands allow multiple entries in the SRC keyword. In versions prior to 2003, GRDCOPY, GRDINFO and GRDLIST allowed multiple entries in SRC, but GRDDISP and GRDIMG allowed only a single entry in SRC. Therefore, you should include that information in your notice, and possibly recommend that they upgrade to McIDAS-X 2003 so they can specify multiple entries in all their GRD* commands.

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. Download the file mccmpgrd.for to the ~oper/mcidas/xcd2003/src directory on your McIDAS-XCD workstation. It will replace the existing version of the file.
3. Recompile the -XCD source code.

From the ~oper/mcidas/xcd2003 directory type:  .  ./xcd_init
From the ~oper/mcidas/xcd2003/src directory type:  make  install.bin

4. Download the file gbtbpds001.av1 to the ~oper/mcidas/data directory on your McIDAS-XCD workstation. It will replace the existing version of the file.
5. Change the real-time grid configuration file so that all GFS (formerly AVN/MRF) grids will be filed into the same grid file range.

   1. Edit the file ~mcidas/data/RTMODELS.CFG
   2. Delete or comment out the line beginning with MRF=
   3. Change the line that begins with AVN= so that it begins with GFS=
   4. Save and close the file

6. Login as user mcadde and create a dataset named RTGRIDS/GFS.

Note: This procedure will retain the old datasets (RTGRIDS/AVN and RTGRIDS/MRF) so that your users will not have to switch to the new dataset (RTGRIDS/GFS) immediately. When all of your users have switched to the new dataset you may delete the old ones.

1. Edit the file ~mcadde/mcidas/data/RESOLV.SRV
2. Copy the line that begins with N1=RTGRIDS,N2=AVN and paste it directly beneath the original line
3. In the line you just added, change N2=AVN to N2=GFS
4. Find the line that begins with N1=RTGRIDS,N2=MRF and change the grid file range to that of the new line containing N2=GFS
   

The resulting lines should be similar to these:

N1=RTGRIDS,N2=MRF,TYPE=GRID,RT=Y,K=GRID,R1=5701,R2=5900,C=Real-Time MRF Grids,
N1=RTGRIDS,N2=AVN,TYPE=GRID,RT=Y,K=GRID,R1=5701,R2=5900,C=Real-Time AVN Grids,
N1=RTGRIDS,N2=GFS,TYPE=GRID,RT=Y,K=GRID,R1=5701,R2=5900,C=Real-Time GFS Grids,

Note that all three of these datasets point to the same grid file range.

5. Save and close the file

7. From a McIDAS-X session running under the oper account, restart -XCD

Type:  STARTXCD

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