In this exercise, you will display and compare grids from two different models, and then display a loop of grids.

Displaying Grid Data over an Image

1. Display the previous day's 48 hour 700 mb relative humidity forecast from the 12:00 UTC GFS model run in green over the current Meteosat image.

   Select:  Display/Grid

   Select:  Dataset/RTGRIBS/GFS-GLME

   If the RTGRIBS/GFS-GLME dataset contains too many grids to sort, a day and time modification box will pop up for you to narrow the search and try again.

   Enter:   yesterday's Julian day

   Select:  Time/12

   Click:   OK

   Select:  Parameter/RH

   Select:  Level/700 MB

   Click:   the 48 hour forecast (third from the bottom)

   Click:   the Options tab

   Select:  Contour Color/Green

   Click:   Load Grid(s)

2. Load the same data from the ECM model run in a different color and compare the results between the two models.

   Select:  Contour Color/a different color of your choice

   Click:   the Data tab

   Select:  Dataset/RTGRIBS/ECM-GLME

   Select:  Parameter/RH

   Select:  Level/700 MB

   Select:  Date/yesterday

   Select:  the 12:00 UTC 48 hour forecast

   Click:   Load and Dismiss

Displaying and Looping Grid Data on a map

1. Erase the images and graphics on frames 1-6.

   Click:   Erase Image

   Click:   Erase Graphics

   Click:   Advance Frame

   Repeat process until all frames have been erased.

2. Select the 24 hour MSL pressure forecast from the March 13, 1993 00:00 UTC NGM model run (valid 14 MAR 00:00 UTC) to be displayed on frame 5.

   Select:  Display/Grid

   Select:  Select Frame/ALL FRAMES/5

   Select:  Dataset/BLIZZARD/GRIDS

   Select:  Source/NGM

   Select:  Parameter/P

   Select:  Date/13 Mar 1993

   Click:   the 24 hour forecast (second in the list)

3. Display the grid over the United States.

   Click:   the Options tab

   Select:  Map Boundaries/USA

   Click:   Load Grid(s)

4. Display the same grid, but this time as part of a loop in frames 1-3.

   Click:   the Data tab

   Select:  Select Frame/Satellites/1

   Select:  the first three grids in the list by clicking the first grid and dragging your mouse down over the next two grids listed

   Click:   Load and Dismiss

5. Loop the grids to see the movement of the Low Pressure System.

   Click:   Play

6. When done viewing the grids, stop the loop.

   Click:   Stop

7. Erase the images and graphics on frames 1-6.

   Select:  Show Frame/ALL FRAMES/1

   Click:   Erase Graphics

   Click:   Advance Frame

   Repeat process until all frames have been erased.