GEMPAK Manual | Programs | Parameters

     SNPARM

     SNPARM is a list of upper air parameters to be used in an upper-air 
     program.

     The four-character parameter names must be separated by semicolons.  
     For example:

		SNPARM = PRES;TMPC;DWPC;THTA

     If a parameter is not present in a data set, the program will attempt 
     to derive it from those parameters which are present.  For example, 
     if pressure, temperature and dewpoint are present in a data set, 
     then relative humidity can be derived. 

     In plotting programs, the position of the parameter determines
     where it will appear with respect to the station location.
     The first position is centered on the station.  The other
     positions are shown below:

				8
			2	10	4
			3	1	5
			6	11	7
				9

     In the example above, DWPC is plotted in position 3.
  
     The layer parameters are computed over a default layer between the 
     specified level and the next level upward in the sounding.  The depth 
     of the layer for layer averages may be specified preceded by ! in the 
     user input.  The shear and RICH calculations can be done relative to 
     a direction by specifying the direction preceded by $ in the user input.

     In-line functions can be used to modify/qualify the output parameters.  
     These functions are applied in the order given; however, arithmetic
     operators must precede other operators.  The function symbols must
     precede the qualifying value and are defined as follows:

	*	multiply			=	equal to
	/	divide			        $	direction
	+	add			        %	vertical coordinate
	-	subtract			!	depth
	<	less than or equal to           
	>	greater than or equal to        

     In the case of wind symbols, the size, line width, type and headsiz
     (arrows) for drawing the symbol may be specified following a colon 
     after the symbol name and after the function specifications if any 
     exist.  The drawing attributes are separated by colons.  The type 
     is a three-digit number, ABC, interpreted digit by digit as follows:

            A                       B                      C
        1 = plot calm wind   1 = start at stn        1 = not filled
        2 = ignore calm wind 2 = center at stn       2 = filled
                             3 = start on sky symbol 3 = not filled with box
                                                     4 = filled with box

     Calm winds are plotted as a circle or an arrowhead for barbs and
     arrows, respectively.  Arrowheads and 50-unit barb flags are filled
     if C=2 or 4. A box is plotted with background color if C = 3 or 4.
     For example, if TYPE=122, a barb will be plotted as a circle if the 
     wind is calm; it will be centered on the station location, and 50-unit 
     flags will be filled.  The default is 111.

     Aliases were created to make it easier for the user to plot typical
     sounding data by using pre-set parameters and colors.  To use an
     alias, enter the alias name for SNPARM and leave COLORS blank. If the
     user does not leave COLORS blank, the selected colors will be used 
     instead of the pre-set alias colors.

     See PRMLST.TBL for a list of current aliases for sounding data.

     The GEMPAK sounding parameters and the corresponding four-character 
     abbreviations are:


		TEMPERATURES

	TMPC - Temperature in Celsius
	TMPF - Temperature in Fahrenheit
	TMPK - Temperature in Kelvin
	THTA - Potential temperature in Kelvin
	THTE - Equivalent potential temperature in Kelvin
	THTS - Saturation equiv. pot. temp. in Kelvin
	THTV - Virtual potential temperature in Kelvin
	TVRK - Virtual temperature in Kelvin
	TVRC - Virtual temperature in Celsius
	TVRF - Virtual temperature in Fahrenheit

		MOISTURE PARAMETERS

	DWPC - Dewpoint in Celsius
	DWPF - Dewpoint in Fahrenheit
	DWPK - Dewpoint in Kelvin
	DPDC - Dewpoint depression in Celsius
	DPDF - Dewpoint depression in Fahrenheit
	DPDK - Dewpoint depression in Kelvin
        DPDX - Dewpoint depression in Celsius; if .ge. 30 plotted as an "X"
	MIXR - Mixing ratio in g/kg
	MIXS - Saturation mixing ratio in g/kg
	PWTR - Precipitable water (mm) up to the specified level
	RELH - Relative humidity in percent
	TMWK - Wet bulb temperature in Kelvin
	TMWC - Wet bulb temperature in Celsius
	THWC - Wet bulb potential temperature in Celsius
	TMWF - Wet bulb temperature in Fahrenheit
	VAPR - Vapor pressure in millibars
	VAPS - Saturation vapor pressure in millibars
	LHVP - Latent heat of vaporization in J/kg

		HEIGHT 

	HGHT - Height in meters
	HGTM - Height in meters (alternate name)
	HGTK - Height in kilometers
	HGTD - Height in decameters
	HGFT - Height in feet
	HGFH - Height in hundreds of feet
	HGFK - Height in thousands of feet
	HGML - Height in miles
	STDZ - Character standard height convention used on upper air charts
	RSTZ - Numeric standard height convention used on upper air charts
	DHGT - Dry hydrostatic height in meters
	MHGT - Moist hydrostatic height in meters

		PRESSURE AND ALTIMETER

	PRES - Station pressure in millibars
	PMSL - Mean sea level pressure in millibars
	ALTI - Altimeter setting in inches from PRES

		WINDS                 

	ARRW - Wind arrow (m/s)
	ARRM - Wind arrow (m/s)
	ARRK - Wind arrow (knots)
	BARB - Wind barb (m/s)
	BRBM - Wind barb (m/s)
	BRBK - Wind barb (knots)
	DARR - Wind direction arrows of uniform length
	UWND - U component of the wind in meters/second
	VWND - V component of the wind in meters/second
	UKNT - U component of the wind in knots
	VKNT - V component of the wind in knots
	DRCT - Wind direction in degrees
	SPED - Wind speed in meters/second
	SKNT - Wind speed in knots
	PSPD - Packed speed and direction (ddfff) in meters/second
	PKNT - Packed speed and direction (ddfff) in knots
	WCMP - Wind component toward a specific direction
	WNML - Wind component toward 90 deg from a specific direction

		LIFTED CONDENSATION LEVEL

	TLCL - Temperature in Kelvin of parcel raised to LCL
	PLCL - Pressure in millibars of parcel raised to LCL

		STABILITY INDICES

 	Note:  Default depths are enclosed in parentheses.

	SHOW - Showalter Index
	LIFT - Lifted Index  (100 mb)
	LFTV - LIFT computed by using virtual temperature
	SWET - Sweat Index
	KINX - K Index
	CTOT - Cross Totals Index
	VTOT - Vertical Totals Index
	TOTL - Total Totals Index
	CAPE - Convective Available Potential Energy  (500 m)
	CAPV - CAPE computed by using virtual temperature
	CINS - Convective Inhibition  (500 m)
	CINV - CINS computed by using virtual temperature
	EQLV - Equilibrium Level (500 m)
	EQTV - EQLV computed by using virtual temperature
	LFCT - Level of Free Convection
	LFCV - LFCT computed by using virtual temperature
	BRCH - Bulk Richardson Number  (500 m, 6000 m)
	BRCV - BRCH computed by using CAPV
	MLTH - Mixed layer mean potential temperature (500 m)
	MLMR - Mixed layer mean mixing ratio  (500 m)
	LCLT - Temperature in Kelvin of the LCL
	LCLP - Pressure in millibars of the LCL
	PWAT - Precipitable water (mm) for the whole sounding

		LAYER QUANTITIES

 	Note:  Default depths are the layer depths in the sounding
 	except for SEPA for which the layer depth is 5 K.

	RICH - Richardson number
	BVFQ - Brunt-Vaisala frequency
	BVSQ - Brunt-Vaisala frequency squared
	BVPD - Brunt-Vaisala period
	LAPS - Temperature lapse rate
	STAB - Potential temperature lapse rate
	STAP - Stability with respect to pressure in k/mb
	SHRM - Wind shear magnitude
	SHRD - Wind shear direction
	SEPA - Vertical separation in mb between isentropes

		STATION VARIABLES

	STID - Character station identifier
	STNM - 5-digit station identifier
	SLAT - Station latitude in degrees
	SLON - Station longitude  in degrees, West is negative
	SELV - Station elevation in meters
	RANG - Range (specialized data)
	AZIM - Azimuth (specialized data)
	LATI - Latitude in degrees
	LONG - Longitude in degrees, West is negative
	DELT - Delta time (specialized data)
     
		MISCELLANEOUS

	DDEN - Density of dry air in kg/(m**3)
	PSYM - Montgomery stream function
	MARK - Markers
	TEXT - Undecoded data
	LHAN - Low level Haines Index
	MHAN - Middle level Haines Index
	HHAN - High level Haines Index

		SPACING

	SPAC - Plot a space, accounted for in FILTER
	BLNK - Plot a blank, not accounted for in FILTER