GEMPAK Analysis and Rendering Program (GARP) Training Exercise 
Prepared by Henry Steigerwaldt 
 

GOAL:   To learn about some of the features of the GARP Program.     

(NOTE:  If the GARP program is currently executing, exit the program. Then 
start the program again, so the program uses its default settings).


1)   Execute the GARP Program by clicking on the GARP icon.


2)   When the GARP window appears, click on the RESET icon.


3)   Select a series of images and create a 48-hr loop.

      a)   Click on MODEL PLAN PROJECTION (icon #5).

      b)   If ETA is not displayed in the model selection box that is used to 
           select the gridded data for a particular model (upper left), click
           on this box and click on ETA model.

      c)   If PRESSURE is not displayed in the box below the model selection 
           box, click on this box and click on PRESSURE.      

      d)   Click on LEVEL 1 button.

      e)   In the window that appears, click on 500 to choose the 500 mb 
           level.

      f)   Under the DATE/TIME heading, click on F000 to choose the initial 
           analysis (00-hr) and while holding down the left mouse button, move
           the cursor to the 48-hr forecast and then release the button.

      g)   Under the SCALAR FIELD, click on HGHT_M to choose the height in 
           meters.

      h)   Click on DISPLAY & CLOSE to close the window and load the images.

      i)   Click on the >> ANIMATION CONTROL BUTTON to loop the images forward 
           (or as long as the mouse cursor is in the GARP Window, strike the L
           key on the keyboard).
            
      j)   Slow the speed of the animation by clicking on the SPEED SLIDER 
           BAR, and while holding down the left mouse button, move the slider bar to the 
           left and release the button.


4)   Let's add another field to the loop we have previously created.

      a)   Click on the o ANIMATION CONTROL BUTTON to stop the animation (or 
           strike the L key on the keyboard).

      b)   Click on MODEL PLAN PROJECTION (icon #5).

      c)   Under the SCALAR FIELD, click on AVORADVECT_S-2 to choose advection
           of absolute vorticity.

      d)   Click on MORE>> (lower right). 

      e)   Click on TYPE box (upper left) to define the appearance of the 
           second field.

      f)   Click on SHORT DASHED so the isopleths of advection of absolute 
           vorticity will be displayed as short dashed lines.

      g)   Click on INTERVAL box. Use the right arrow on the keyboard and 
           move the cursor as far to the right as it will go. Use the
           backspace key to erase the existing numbers.

      h)   Enter the number 40.

      i)   Click on MINIMUM box. Use the right arrow on the keyboard and move 
           the cursor as far to the right as it will go. Use the backspace
           key to erase the existing numbers.

      j)   Enter the number 1.

      k)   Click on CLOSE (at bottom).

      l)   Click on DISPLAY & CLOSE to close the window and load the images.

      m)   Click on the >> ANIMATION CONTROL BUTTON to loop the images  
           forward.             

5)   Select a layer-type product and create a loop using only 12-hr forecasts.

      a)   Click on RESET icon.      

      b)   Click on MODEL PLAN PROJECTION (icon #5).
 
      c)   Click on LAYER button (lower left).

      d)   Click on LEVEL 1 button (upper left).

      e)   In the window that appears, click on 700 to choose the 700 mb level.

      f)   Click on LEVEL 2 button (upper left).

      g)   In the window that appears, click on 1000 to choose the 1000 mb level.

      h)   Under the DATE/TIME heading (at left), click on the F012 (12-hr) 
           forecast. Then hold down the CONTROL KEY and click on F024, F036
           and F048  (24-, 36- and 48-hr) forecasts and release the key.

      i)   Under the SCALAR FIELD, click on THICKNESS_M.

      j)   Click on MORE >>.

      k)   Click on the INTERVAL box (left side). Use the right arrow on the 
           keyboard and move the cursor as far to the right as it will go. Use
           the backspace key to erase the existing numbers. 

      l)   Enter the number 30 (30-meter) in the INTERVAL box. 

      m)   Click on LABEL box and click on EVERY 4TH CONTOUR.

      n)   Under the word SYMBOL (lower left), click on the HI/LOW button (if 
           it is not already depressed) to label the maximum and minimum
           centers of 1000-700 mb thickness on the display. 

      o)   Click on CLOSE.

      p)   Click on DISPLAY & CLOSE to close the window and load the images.

      q)   Click on the >> ANIMATION CONTROL BUTTON to loop the images 
           forward. 


6)   Display a Satellite Image and overlay model data onto the image to 
     compare the model forecast with the satellite image. (NOTE:  In order to
     overlay model data onto a satellite image, you must always select the
     satellite image first before selecting the model data. Also,
     the model forecast time should match as closely as possible the time of 
     the satellite image in order to make a valid comparison).

      a)   Click on RESET icon.

      b)   Click on AREA (at top), then click on SOUTHEAST. This selects the 
           Southeast map background. 

      c)   Click on RADAR and SATELLITE DATA (icon #1).    

      d)   Click on GOES-8, 12KM and IR buttons.

      e)   Click on an image valid around 18 UTC.

      f)   Click on LOAD IMAGES. 

      g)   Click on MODEL PLAN PROJECTION (icon #5).

      h)   Click on LEVEL 1 button.

      i)   In the window that appears, click on 500 to choose the 500 mb level.

      j)   Under the DATE/TIME heading, click on the forecast time closest 
           to the image time. For a model run of 12 UTC, you would use the
           F006 (06-hr) forecast valid at 18 UTC.

      k)   Under the VECTOR FIELD, click on WIND_MS-1.

      l)   Click on MORE>>.

      m)   Click on the TYPE box under VECTOR SYMBOL heading. 

      n)   Click on STREAMLINES.

      o)   Click on CLOSE.
      
      p)   Click on DISPLAY & CLOSE to close the window and overlay the model data.


7)   Select and display a cross section between two locations. (NOTE:  One can
     use any two points desired. But if one wants to select a cross section 
     through a jet streak for example, display a relevant graphic using the 
     MODEL PLAN PROJECTION (icon #5) to determine the end points of the cross
     section (see below)).

      a)   Click on RESET icon.

      b)   Click on MODEL PLAN PROJECTION (icon #5).

      c)   Click on LEVEL 1 button.

      d)   In the window that appears, click on 300 to choose the 300 mb level.

      e)   Under the DATE/TIME heading, click on a time (F024 for example). 

      f)   Under the SCALAR FIELD, click on ISOTACH_KTS-1 to choose isotachs  
           in knots. (NOTE:  You may have to use the scroll bar to right of
           window to be able to display the file in the window for selection).

      g)   Click on DISPLAY & CLOSE to close the window and load the image. 
           Move the  mouse cursor to the desired end points of the cross
           section and read the latitude and longitude of the end points on
           the bottom line of the GARP Window.
   
      h)   Click on RESET icon.

      i)   Click on MODEL CROSS SECTION (icon #6).

      j)   Click on CROSS SECTION box  (upper left). Use the right arrow on 
           the keyboard and move the cursor as far to the right as it will
           go. Use the backspace key to erase the existing numbers. 

      k)   Enter the latitude and longitude of the end points. Example:  
           35.1;-90.0>36.1;-86.7     
           (NOTE:  Longitude is always entered as a negative value. You can 
           also enter two identifiers, such as MEM>BNA for example).

      l)   Under the DATE/TIME heading (at left), click on the model time 
           that matches as closely as possible the valid time of the graphic
           that was selected using the MODEL PLAN PROJECTION (F024 in this example).

      m)   Under the SCALAR FIELD, click on ISOTACH_KTS-1to choose isotachs in
           knots.

      n)   Click on DISPLAY. 

      o)   Under the SCALAR FIELD, click on OMEGA_MBS-1 to choose vertical 
           motion in microbars per second. 
     
      p)   Click on DISPLAY & CLOSE to close the window and load the image.


8)   Exit the GARP Program.

      a)   Click on FILE (top left).

      b)   Click on QUIT in the window that appears.