AREA
 
     AREA is the data area.  Only data within the area specified will be 
     processed.

     Areas may be defined containing subareas.  Subareas must be separated 
     by slashes.  Each subarea is additive, +, or subtractive, -, depending 
     on the first character following the slash, with + being the default.  
     Additive subareas add stations to the list of valid stations; 
     subtractive subareas eliminate stations which were previously valid.
 
     Subareas may be specified in the following ways:
 
     1.  lat1;lon1;lat2;lon2 
         This defines a latitude/longitude range where (lat1, lon1) is the 
         lower left corner and (lat2, lon2) is the upper right corner.  
         West longitude is negative.
   
         #clat;clon;dlat;dlon
         This defines a latitude/longitude range by the center latitude and 
         longitude.  The lower left corner is (clat-dlat; clon-dlon); the 
         upper right corner is (clat+dlat; clon+dlon).  No corrections are 
         made for the poles or the International Date Line.
 
     2.  GEOG
         This is an abbreviation for a geographic area defined in the 
         GEMPAK geographic table which includes abbreviations for states, 
         provinces, and countries, as well as other names. A suffixed + or * 
	 will decrease the extent of the geographic area. A suffixed - will 
	 increase the extent of the geographic area. 
 
     3.  STN
         This defines an area centered on a station found in the GEMPAK 
         station table.  A suffixed + or * will decrease the extent
         of the geographic area.  A suffixed - will increase the extent
         of the geographic area.
 
     4.  DSET 
         This includes all the stations in the current data set.
 
     5.  @ST  
         This area includes those stations located in the state, province 
         or country defined by ST.  Only some countries are recognized 
         (US,CN,MX,CI,BW,AU); other countries may be specified using method 6.
 
     6.  @CN:C
         This area includes those stations located in the country defined 
         by CN.
 
     7.  @STN1;STN2;...;STNn 
         This area includes the stations listed, where STNi may be a station 
         identifier or a station number.
 
     8.  SHDR:iloval:ihival 
         This area defines a range of integer values for the station header, 
         SHDR.  Valid keywords for SHDR are:
 
		COUN	--	country
		SELV	--	elevation (in meters)
		SLAT	--	latitude (in degrees x 100)
		SLON	--	longitude (in degrees x 100, West is negative)
		SPRI	--	priority
		STAT	--	state
		STID	--	character identifier
				(6 digits for surface--usually the WMO
				 5-digit number followed by a 0)
 
         where COUN, STAT and STID are not very useful, since the integer 
         representation of characters is system dependent.
  
         For example, SELV:0:2000 specifies stations whose elevations are 
         less than 2000 meters.

     9. GAREA
	This area corresponds to a slightly larger area than that specified
	by GAREA.  It will ensure that data will appear near the bounds of 
	the view region.