GEMPAK Parameter Help (Hypertext Version)

	A:	ADDSTN		ANLYSS		AREA
	B:	BORDER
	C:	CINT		CLEAR		COLORS
		CPYFIL		CTLFLG		CTYPE
		CURVE		CXSTNS
	D:	DATTIM		DELTAN		DELTAX
		DELTAY		DEVICE		DTAAREA
	E:	EXTEND
	F:	FILTER
	G:	GAMMA		GAREA		GDATTIM
		GDEFIL		GDFILE		GDNUM
		GDOUTF		GFUNC		GLEVEL
		GNAME		GPACK		GPARM
		GPOINT		GRDAREA		GRDNAM
		GUESS		GVCORD		GVECT
	I:	IDNTYP
	K:	KXKY
	L:	LATLON		LEVELS		LINE
	M:	MAP		$MAPFIL		MARKER
		MAXGRD		MIXRLN		MRGDAT
	N:	NPASS		NTRACE
	O:	OUTPUT
	P:	PANEL		POSN		PROJ
		PTYPE
	R:	REGION		$RESPOND
	S:	SAVFIL		SCALE		SEARCH
		SFEFIL		SFFILE		SFOUTF
		SFPARM		SFPRMF		SHIPFL
		SKIP		SKPMIS		SNEFIL
		SNFILE		SNOUTF		SNPARM
		SNPRMF		SOURCE		STATION
		STNCOL		STNDEX		STNFIL
	T:	TAXIS		TEXT		THTALN
		THTELN		TIMSTN		TITLE
		TRACE
	V:	VCOORD
	W:	WIND		WINPOS
	X:	XAXIS
	Y:	YAXIS

Comments and errors to: peggy@unidata.ucar.edu

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ADDSTN ADDSTN is a logical variable which indicates whether stations which are in STNFIL , but not already included in the data file, should be added to the data file. Enter YES to add stations. Enter NO to update current stations but not add new ones. .
ANLYSS ANLYSS is the average station spacing and the grid extend region separated by a slash: station spacing / grid extend region This information is retrieved from the grid file and used in the objective analysis programs. The station spacing is in degrees of latitude and is used to compute the weighting functions in the Barnes analysis programs. The default for the station spacing is twice the grid spacing. The grid extend area is specified by four integers, separated by semicolons, which are the numbers of grid points to extend the grid left, down, right, and up. Only data within the extended grid area is used after the first Barnes pass. The default for the grid extend region is 2;2;2;2. .
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. If #GEOG is entered, the user geographic table, GEOG.TBL, will be searched. A suffixed + or * will expand, and - will reduce the area. 3. STN This defines an area centered on a station found in the GEMPAK station table, which currently contains US, Canadian and Mexican surface stations. A suffixed + or * will expand, and - will reduce the 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) 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. .
BORDER BORDER is the color, line type and line width of the plot background separated with slashes: color / line type / line width If the color is 0, no background will be drawn. The defaults for color, line type and line width are each 1. .
CINT CINT is the contour interval, minimum and maximum values separated by slashes: contour interval / minimum / maximum The contour interval may be any real number. If it is not specified or if the value is 0, the program will select an interval which will generate 5 to 10 contour levels. The minimum and maximum values specify the range of data to use in selecting contour levels. If either value is not specified, the value will be obtained from the range of values in the dataset. If the minimum and maximum are equal, that value will be used and only one contour level will be selected. A list of two or more contour levels may be entered using semicolons to separate the individual values. In this case, the minimum and maximum are ignored. .
CLEAR CLEAR is a logical variable which determines whether the graphics screen is cleared before plotting. Enter YES to clear screen or NO to leave current graphics. .
CLRBAR CLRBAR specifies the characteristics of a color bar associated with contour fill. The attributes are separated by slashes: color / orientation / anchor / x;y / length;width / frequency Color is the color of the labels and the bounding box around the color bar. If color is negative, the bounding box will not be drawn, and labels will be drawn in colors corresponding to the color bar. If the color is 0 or missing, no color bar is drawn. Orientation specifies a vertical or horizontal orientation of the color bar where 'V' is a vertical bar and 'H' is a horizontal bar. The default is 'V'. Anchor describes the location on the color bar corresponding to the location given in the next parameter. Valid inputs are LL, LC, LR, CL, CC, CR, UL, UC, and UR for lower-left, lower-center, lower-right, center-left, centered, center-right, upper-left, upper-center, and upper-right, respectively. For example, an 'LL' anchor point, with a x;y of .1,.1, will place the lower-left corner of the color bar at view coordinates .1, .1. The default anchor point is 'LL'. x;y is the position for the anchor point of the color bar in view coordinates. The default is .005, .05. Length;width are the length and width of the color bar, normalized to the view coordinates. The defaults are .5 for the length, and .01 for the width. Frequency describes the levels to be labeled. If the frequency is positive, the labels are plotted on the right/top of the color bar. If it is negative, the labels are plotted on the left/bottom of the color bar. The default is -1. To disable the color bar, set CLRBAR = 0 or leave it blank. If only contour lines are drawn (CTYPE = C), the CLRBAR variable is not used. Examples: CLRBAR = 1 text and bounding box in color 1; defaults for the rest of the input; CLRBAR = 5/V/ /.25;.1/1 text and bounding box in color 5; color bar plotted vertically; length and width .25 and .1 of the view window; all intervals labeled along left side of the color bar; color bar anchor point at lower-left; CLRBAR = 1//CL/.1;.5/.75;.1 text and bounding box in color 1; length and width .75 and .1 of the view window; center-left of the color bar positioned at .1;.5 in view coordinates; .
COLORS COLORS specifies a list of color numbers which must be separated using semicolons: color 1 ; color 2 ; ... ; color n The color list will be repeated, if necessary, to determine all colors required by the program. Colors may be entered as a range in the form: first-last-increment. If the increment is not entered, 1 is assumed. If the input is blank, a default of 1 is used. If a color number of 0 is entered, that parameter or line will not be plotted. New color assignments may be made by appending the following commands to the color number: =INIT -- all colors are initialized to device-dependent colors =NAME -- this color number is set to the color specified in NAME =r:g:b -- this color number is set using RGB components in r, g, and b which must be separated using colons. These components must be in the range 0 - 1. Note that only =INIT may be appended to a range. The following colors are the default colors for the given devices: XW,NC PS,PSP PSC GEMPAK NAMES X COLOR NAMES 1 31 VANILLA bisque1 2 2 RED red 3 3 GREEN green 4 4 BLUE blue 5 5 YELLOW yellow 6 6 CYAN cyan 7 7 MAGENTA magenta 8 8 BROWN sienna3 9 9 CORAL sienna1 10 10 APRICOT tan1 11 11 PINK LightPink1 12 12 DKPINK IndianRed1 13 13 MDVIOLET firebrick2 14 14 MAROON red4 15 15 FIREBRICK red3 16 16 ORRED OrangeRed2 17 17 ORANGE DarkOrange1 18 18 DKORANGE orange3 19 19 GOLD gold1 20 20 DKYELLOW yellow2 21 21 LWNGREEN chartreuse1 22 22 MDGREEN green3 23 23 DKGREEN green4 24 24 GRPBLUE DodgerBlue4 25 25 LTBLUE DodgerBlue1 26 26 SKY DeepSkyBlue2 27 27 MDCYAN cyan2 28 28 VIOLET MediumPurple3 29 29 PURPLE purple2 30 30 PLUM magenta4 31 31 WHITE white 32 1 1 BLACK black 2 G95 gray95 3 G90 gray90 4 G85 gray85 5 G80 gray80 6 G75 gray75 7 G70 gray70 8 G65 gray65 9 G60 gray60 10 G55 gray55 11 G50 gray50 12 G45 gray45 13 G40 gray40 14 G35 gray35 15 G30 gray30 16 G25 gray25 17 G20 gray20 18 G15 gray15 19 G10 gray10 20 G05 gray5 On the color devices, colors 8 through 30 will provide a range of colors from brown to red to orange to yellow to green to blue to violet. On the Postscript device, 20 gray shades are used. .
CONTUR CONTUR sets attributes for the contour algorithms: subbox factor / number of smoothing passes Each grid box will be subdivided into the number of subboxes specified by the subbox factor. Increasing this value will produce smoother contours, but will increase contouring times and make metafiles larger. The new default value in GEMPAK 5.2 is 0. A simple three-point smoothing filter is used if the number of smoothing passes is greater than 0. The default is 0. .
CPYFIL CPYFIL identifies the location of the grid navigation and analysis information to be stored in a grid file. Three options are available: 1. If CPYFIL is blank, the information is taken from the input for PROJ , GRDAREA , KXKY , and ANLYSS . 2. If CPYFIL begins with a #, the information is read from the line in the grid navigation table which has the grid name or number corresponding to the rest of CPYFIL . 3. If CPYFIL is the name of a current grid file, the grid and navigation information will be copied from that file. Note that if CPYFIL is not blank, the values of PROJ , GRDAREA , KXKY , and ANLYSS will be ignored. .
CTLFLG CTLFLG is a logical flag which indicates whether control characters are included in a raw surface data set to be decoded. The raw surface data set must contain either bulletins from the Domestic Data Service or single station reports. If the data set contains bulletins, set CTLFLG = YES. Otherwise, it will be assumed that the file contains single station reports with one report per line. If CTLFLG = YES, the input file must contain bulletins. If CTLFLG = NO, the file must have reports. .
CTYPE CTYPE specifies the contouring algorithms to use separated by slashes: type 1 / type 2 / ... / type n Valid inputs for type are: C the original GEMPAK contouring algorithm L contouring based on Lagrangian computations (same as C) F contour fill algorithm S spline algorithm -- not implemented B box algorithm -- same as contour fill, but draws lines around the polygons rather than filling in polygons. Note that contour attributes are specified in CONTUR . The contour interval and line characteristics for types C, L, S and B are read from CINT and LINE and for type F from FINT and FLINE . Examples: CTYPE = C -- draws contour lines CTYPE = C / F -- draws filled contours overlaid with lines .
CURVE CURVE is a number corresponding to the method to be used to fit the curve. Generally, CURVE should be set to 2. The curve types currently available are: 1 - piecewise straight line 2 - cubic spline 21 - cubic spline with linear ends 22 - cubic spline with parabolic ends 23 - cubic spline with extrapolated ends Note that types 2 and 21 are the same. Types 22 and 23 produce slightly different results at the ends of the splines. .
CXSTNS CXSTNS defines the x-axis for a cross-section plot. In SNCROSS, CXSTNS is the list of stations, separated with semicolons, to be used for the cross section. Stations may be entered using either character or numeric identifiers. In GDCROSS, CXSTNS contains the endpoints of the cross-section line separated using a >. Each endpoint may be defined as follows: 1. a station character or numeric identifier; 2. a latitude and longitude pair separated by a semicolon; 3. an @ followed by a grid x and y coordinate pair separated using a semicolon, e.g., @1.5;2.3>@25.9;30. .
DATTIM DATTIM is the date and time to be used by GEMPAK programs. DATTIM is an 11-character string entered as YYMMDD/HHMM, where: YY is the last two digits of the year MM is the month DD is the day of the month / is the date and time separator HH is the hour MM is the minutes past the hour The part before the / is the DATE; the part after the / is the TIME. DATTIM may be abbreviated. If the input has no / , it is assumed to be the TIME part. An abbreviated version of either TIME or DATE is assumed to be the part closest to the /. The rest of the standard time is obtained from the last time in the file. For example, if the last time in the file is 940515/1200 the following translations will be done: 13/11 ----> 940513/1100 13 ----> 940515/1300 13/ ----> 940513/1200 0412/1300 ----> 940412/1300 A list of times may be entered for DATTIM . Times in the list must be separated with semicolons. For example: 13/11;0412/13;0515/6 In the above example, the times are: 940513/1100 940412/1300 and 940515/0600. DATTIM may also be entered as a range. The first and last times must be separated by a minus sign. For example: 13/11-15/14 A range with an increment may also be entered using minus signs as separators. The format of the increment is hhhmm. If the increment is one or two digits, it is assumed to be in hours. The following options are also valid for DATTIM : LAST -- the last time in the file LIST -- lists all times and waits for input ALL -- all the times in the file /ALL -- all the times for a single DATE. If /ALL is entered, all the times for the most recent date are processed. If /ALL is appended to a specific date, then all the times for that date will be processed. .
DELTAN DELTAN is the average station spacing in degrees of latitude. The Barnes objective analysis programs use this number to compute weights for data interpolation. .
DELTAX DELTAX is the spacing between grid points in the x direction on CED grids. This value is in degrees longitude. .
DELTAY DELTAY is the spacing between grid points in the y direction on CED grids. This value is in degrees latitude. .
DEVICE DEVICE specifies the graphics device: device | name The following valid graphics devices may be available: XW : X Windows terminal NC : NTRANS CGM VC : Standard (vanilla) CGM PSC : PostScript / landscape / 32 colors PSP : PostScript / portrait / 20 gray levels PS : PostScript / landscape / 20 gray levels PS1 : PostScript / landscape / 1 color NAME is the metafile name in the NC driver. If the file already exists, the NC driver will append new frames, unless the name specified is Nmeta. Nmeta is the default name; a new file will be created each time the file used is Nmeta. In the XW driver, NAME specifies the window to be used. Up to 5 windows may be opened. A default window named GEMPAK 5.2 is always opened. NAME is not currently implemented in VC or Postscript drivers. .
DTAAREA DTAAREA defines the area over which station data will be input to the Barnes objective analysis. Since data must be interpolated from the first pass grid back to stations, only data within the EXTEND area will be used after the first pass. If the DTAAREA is not specified by the user, it will default to the EXTEND area in OAGRID or to the data area stored in the grid file analysis block in OABSFC and OABSND. DTAAREA can be specified in three 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. If #GEOG is entered, the user's geographic table, GEOG.TBL, will be searched. A suffixed + or * will expand, and - will reduce the area. 3. STN This defines an area centered on a station found in the GEMPAK station table, which currently contains US, Canadian and Mexican stations. A suffixed + or * will expand, and - will reduce the area. Note that the other ways of specifying AREA are not valid for DTAAREA in OAGRID but are valid in both OABSFC and OABSND. For all projections, the lat/lon corners defined will be used exactly. For projections which include the pole, if lat1 = lat2 and lon1 = lon2, then lat1 will specify the range of data from the pole and lon1 will specify the central longitude. West longitude is negative. Note that the stations actually used for the data area may be changed in the objective analysis programs using DTAAREA . .
EXTEND EXTEND specifies the numbers of grid points beyond the GRDAREA which define the grid extend area in the Barnes objective analysis. The first pass is computed on the extend area to reduce edge effects on the GRDAREA . EXTEND is specified as four integers, which are the number of grid points to extend the grid left, down, right, and up. The values are separated by semicolons. The default for EXTEND is 2;2;2;2. .
FILTER FILTER is a logical variable or real number which controls the filtering of data in order to eliminate plotting of overlapping data. If FILTER is YES, the data will be filtered. If FILTER is NO, 0, or blank, all data will be plotted. If FILTER is set to a real number, the default filter will be scaled by that number. FILTER = 1 corresponds to FILTER = YES. 0 < FILTER < 1 allows some data overlap. FILTER > 1 causes data to be more widely spaced. .
FINT FINT is the contour fill interval, minimum and maximum values separated by slashes: fill interval / minimum / maximum The contour fill interval may be any real number. If it is not specified or if the value is 0, the program will select an interval which will generate 5 to 10 contour fill levels. The minimum and maximum values specify the range of data to use in selecting the fill levels. If either value is not specified, the value will be obtained from the range of values in the dataset. If the minimum and maximum are equal, that value will be used and only one contour fill level will be selected; however, since the number of colors is one greater than the number of fill levels, two colors will be needed--the first for filling regions with values less than the input value and the second for filling regions of greater value. A list of two or more fill levels may be entered using semicolons to separate the individual values. In this case, the minimum and maximum are ignored. .
FLINE FLINE is the list of colors to be used for contour fill. The number of fill colors needed is one greater than the number of fill levels in FINT . The number may be entered as a list of color numbers separated by semicolons or a range of colors. More information on color selection can be found in the help for COLORS . .
GAMMA GAMMA , the convergence parameter, is a multiplier for the weight and search radius for passes after the first pass of the Barnes analysis programs. GAMMA must be within the range 0 - 1. Any value outside this range will default to a value of 0.3. If GAMMA is 0, the number of passes will be set to 1. The recommended value for GAMMA is 0.3. .
GAREA GAREA is the graphics area. This is the area which will be displayed on a graphics device. GAREA can be specified in the following: 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. If #GEOG is entered, the user's geographic table, GEOG.TBL, will be searched. A suffixed + or * will expand, and - will reduce the area. 3. STN This defines an area centered on a station found in the GEMPAK station table, which currently contains US, Canadian and Mexican stations. A suffixed + or * will expand, and - will reduce the area. 4. SATFIL This specifies a file that contains a McIdas area image file. Note that the other ways of specifying AREA are not valid for GAREA . For all projections, the lat/lon corners defined will be used exactly. For projections which include the pole, if lat1 = lat2 and lon1 = lon2, then lat1 will specify the range of data from the pole and lon1 will specify the central longitude. West longitude is negative. For overlay on McIdas imagery, PROJ must be set to SAT and GAREA must be the file name of the McIdas area file. For animation programs, a list of satellite images, separated by semicolons, may be entered. For long image names, part of the first name may be separated by backslashes ( \ ); the following values in the list will be substituted for the characters within the backslashes, i.e. $GOES7/VIS_941017_\12\01;13;14 is interpreted as $GOES7/VIS_941017_1201;$GOES7/VIS_941017_1301;$GOES7/VIS_941017_1401 .
GBFILE GBFILE is the name of the file which contains gridded data in GRIB messages. .
GDATTIM GDATTIM is the date/time for the grid. Grids may contain two date/time fields, in which case the fields must be separated using a colon. If the grid to be selected contains only one time, the colon and second time may be omitted. The standard format for a grid time is a character string YYMMDD/HHMMthhhmm where: YYMMDD is the year, month, day / is the date and time separator HHMM is the hour, minute t is the type ( F=forecast A=analysis G=guess V=valid ) hhhmm is the forecast hour, minute If t is blank, an analysis grid is assumed. If hhhmm is blank, 00000 is assumed. If hhhmm has one, two, or three digits, they represent hours. With four or more digits, zeros will be added at the beginning of the field. The field YYMMDD is called the date; HHMM is the time; t is the type; hhhmm is the forecast time. The fields may be abbreviated. If the input has no /, it is assumed to be the time part. Any abbreviated version of either date or time is assumed to be the part closest to the /. The rest of the date and time is obtained from the last time in the file. If the type is missing, then A is assumed, and a missing forecast time is replaced by 00000. The type and forecast time fields are used with forecast model data. If GDATTIM is 940831/0000F24, the grid to be found is the 24-hour forecast from the model run at 00Z on Aug 31. If GDATTIM is 940831/0000V24, the grid to be found is the 24 hour forecast valid for 00Z on Aug 31 from the model run at 00Z on Aug 30. Examples (with the last time = 941205/1600 ): GDATTIM TIME1 TIME2 ----------- -------------- ----------- 941205/1200 941205/1200 12:15 941205/1200 941205/1500 LAST 941205/1600 /00F24 941205/0000F24 The value in GDATTIM may be overridden by specifying ^GDATTIM with the grids to be found. For example, GFUNC = SUB (TMPF^28/12,TMPF^27/12) will compute the same time difference as GFUNC = TDF (TMPF) with GDATTIM =28/12:27/12. Note that a grid from an objective analysis will have forecast type and time A00000, which is the default for a blank forecast type and time. .
GDEFIL GDEFIL is the name of the grid edit file which will be used to update a grid file. The edit file must contain only complete grids. GDEFIL is a text file which may be created using the program GDLIST with F as an output device and GAREA = DSET. A text editor may be used to create or change the grid edit file. GDEFIL must contain the following information before the complete grid data: The time, level, vertical coordinate and parameter name MUST appear on the same line in the order given. The time must be a fully qualified GEMPAK time. The parameter name is the name of the grid. The first and last row and column information must appear on one line. Column information must be preceded by the word COLUMNS:. Row information must be preceded by the word ROW:. The first row and column must be 1. The last row and column must be the same as the grid size in the file. For example: COLUMNS: 1 8 ROWS: 1 6 If the string FACTOR:, appears and is followed by an integer, the data will be divided by 10**SCALE before being stored in the grid file. In the following example, the data will be divided by 10**5. SCALE FACTOR: 10**5 The string COLUMN: signals the beginning of the grid data. If the required grid information has not already been found, an error will result. The data for the grid follows the grid keywords. The data for a grid is listed from the top (last) row to the bottom row in the grid. The beginning of each row of data must be preceded by the string ROW. Data consists of numeric values for each data point; missing data should be entered as -9999.0. .
GDFILE GDFILE is the name of the file which contains gridded data. The input for GDFILE may contain more than one file name separated by +. Up to three file names may be entered. Individual operands in GFUNC or GVECT can be accessed from a specific file by placing +n after the operand name, where n is the number corresponding to the placement of the file name in the GDFILE input. In the example below, the temperature from the third file is advected by winds from the first file: GDFILE = file1.grd + file2.grd + file3.grd GFUNC = ADV ( TMPK+3, WND ) .
GDNUM GDNUM allows the user to select grids by number in the following ways: GDNUM = range The first and last grid numbers in the range are separated by a -. If an increment is included, it will be ignored. GDNUM = list The grid numbers in the list are separated using semicolons. GDNUM = ALL All the grids in the file will be included. GDNUM = LIST All the grids in the file will be listed. The user will be prompted to select the grids to be included. .
GDOUTF GDOUTF is the output grid data file name. GDOUTF is used in programs which create a new grid data file. It is also used in programs that move data from an input file to an output file. In that case, GDFILE is the original file. .
GFUNC GFUNC specifies a grid diagnostic function which yields a scalar quantity. For more information, see the GPARM documentation. .
GLEVEL GLEVEL is the vertical level for the grid. Grids may contain two levels separated by a colon. If the grid to be selected contains only one level, the colon and second level may be omitted. In this case, the second level is stored in the grid file as -1. Note that the vertical coordinate system for GLEVEL is specified by GVCORD . The value in GLEVEL may be overridden by specifying @GLEVEL with the grids to be found. For example, the following two computations are identical: GFUNC = SUB (TMPF@850,TMPF@500) GFUNC = LDF (TMPF) and GLEVEL = 850:500. .
GNAME GNAME is the geographic name abbreviation and long name to be saved in a geographic table separated with a slash: geographic name abbreviation / long name The abbreviation may later be input as an area name in AREA or GAREA by prefixing a #. The long name will be saved in the table but will not be used. .
GPACK GPACK is the packing type and the number of bits (or data precision) to be used to pack the grid data, separated with a slash: packing type / number of bits (NONE, GRIB, DIF) packing type / precision (DEC) The valid packing types are: NONE No packing GRIB Data is packed in GEMPAK GRIB format DEC Data is packed in GEMPAK GRIB format DIF Data is packed in GEMPAK DIF format If the packing type is DEC, the number of bits is replaced by the data precision. The data will be scaled by 10**precision and rounded to the nearest integer. The number of bits used to store the data will be the minimum number required to store the resulting integers. If the number of bits is less than 32, the packing type specified will be used. If no packing type is given, the data will be packed using the GEMPAK GRIB scheme. In general, data should be stored using packing type GRIB with 16 bits, by specifying the precision in DEC or with no packing using type NONE. Care should be taken using the other packing options. Pack Type Minimum Maximum Default NONE 32 32 32 DEC -5 5 2 DIF 2 32 16 GRIB 2 32 16 The default data packing when GPACK is blank is GRIB/16. .
GPARM GFUNC and GVECT are the scalar and vector grid functions. They are input as nested strings of operators and operands. The operand list for an operator is enclosed in parentheses or square brackets, with operands separated by semicolons or commas. The following grids will be computed automatically from grids in the grid file, if possible: TMPK DWPK TVRK MIXR THTA DRCT TMWK TMPC DWPC TVRC SMXR STHA SPED TMWC TMPF DWPF TVRF MIXS THTE RELH TMWF SMXS STHE Mixing ratios will be computed automatically from dewpoint temperatures, specific humidity, or vapor pressure if a pressure grid exists. In addition, precipitation will be converted from inches (I) to millimeters (M) and vice versa, if the grids are named P__M or P__I. The middle characters are numbers giving the time interval over which the precipitation accumulated. For example, P24M is a 24-hour precipitation total. The units for sea surface temperature (SSTx), maximum temperature (TMXx), and minimum temperature (TMNx) will be converted automatically. ( x may be K, C, or F. ) These special scalar parameter names denote constant value grids: DTR Conversion factor for degrees to radians = PI / 180 E Base of natural logarithms = 2.71828182 GRAVTY Gravitational constant = 9.80616 (note spelling) KAPPA Gas constant/specific heat = 2/7 PI 3.14159265 RTD Conversion factor for radians to degrees = 180 / PI nnn Any number (e.g., 2, -10.2) Another class of special parameter names depends on the grid navigation: CORL Coriolis force = 2. * OMEGA * SIN ( LATR ) LATR Latitude in radians LONR Longitude in radians XVAL Value of the x coordinate in graph coordinates YVAL Value of the y coordinate in graph coordinates MSFX Map scale factor in x direction MSFY Map scale factor in y direction A grid may be identified by its number in the grid file by prefixing the number with the symbol #, e.g., #5. Standard vector grids are: WND Total wind WIND Alternate name for WND OBS Alternate name for WND GEO Geostrophic wind AGE Ageostrophic wind ISAL Isallobaric wind THRM Thermal wind Time, level, and vertical coordinate as specified through the user interface may be overridden by in-line parameters: ^time @level %ivcord appended to an operand in any combination. If more than one file is opened, +n may also be used as an in-line parameter, where "n" is the number corresponding to the position of the file list entered in GDFILE . If +n is omitted, the first file is used. For example, to advect temperature from file 3 using winds from file 1: GDFILE =file1.grd + file2.grd + file3.grd GFUNC =ADV ( TMPK+3, WND ) Grid operators may be nested. Note that layer and time range operators expect operands read directly from the grid file. GFUNC may include a name for the computed grid. This name may be used in later diagnostic functions in an application. The grid is stored in an internal, circular grid list and will eventually be overwritten. It will never be available after exiting the application. The name is specified after two slashes at the end of GFUNC . For example, GFUNC = DIV ( WND ) // DVRG permits the divergence to be used in a later calculation as DVRG, as in this example: GFUNC = LAP ( DVRG ) This name will also be the default name used in the title. In the following list of diagnostic operators, scalar operands are named Si, and vector operands are Vi. Vector components are denoted by u and v. All meteorological grids are in MKS units, except as noted. POL following the description indicates that the computation currently can only be performed on polar (R, THETA) grids. In the trigonometric functions, the angles are expressed in radians. The scalar constants used as arguments for the radial and tangential wind computations are defined as follows: LAT = latitude of storm center LON = longitude of storm center D = direction of storm motion ST = speed of storm motion SCALAR OUTPUT GRID ABS (S) Absolute value ACOS (S) Arc cosine function ASIN (S) Arc sine function ATAN (S) Arc tangent function ATN2 (S1,S2) Arc tangent function COS (S) Cosine function EXP (S1,S2) Exponential to real EXPI (S1,S2) Exponential to integer [uses NINT(S2)] LN (S) Natural logarithm LOG (S) Base 10 logarithm SIN (S) Sine function SQRT (S) Square root TAN (S) Tangent function ADD (S1,S2) Addition MUL (S1,S2) Multiplication QUO (S1,S2) Division SUB (S1,S2) Subtraction ADV (S,V) Advection AVG (S1,S2) Average AVOR (V) Absolute vorticity CROS (V1, V2) Vector cross product magnitude DDEN (PRES,TMPC) Density of dry air ( kg / m**3 ) DDR (S) Partial derivative with respect to R (POL) DDT (S) Time derivative DDX (S) Partial derivative with respect to X DDY (S) Partial derivative with respect to Y DEF (V) Total deformation DIRN (V) Direction relative to north DIRR (V) Direction relative to grid DIV (V) Divergence DOT (V1,V2) Vector dot product DTH (S) Partial deriv. with respect to THETA (POL) FCNT (S) Coriolis force at grid center (POL) FRNT (THTA,V) Frontogenesis HIGH (S, RADIUS) Relative maxima over a grid (RADIUS is expressed in grid points) JCBN (S1,S2) Jacobian determinant KNTS (S) Convert meters / second to knots LAP (S) Laplacian operator LAV (S) Layer average (2 levels) LDF (S) Layer difference (2 levels) LOWS (S, RADIUS) Relative minima over a grid (radius is expressed in grid points) MAG (V) Magnitude of a vector MASS Mass per unit volume in a layer from PRES MDIV (V) Layer-average mass divergence MIXR (DWPC,PRES) Mixing ratio g/g internally, g/kg on output MRAD (V,LAT,LON, D,ST) Magnitude of radial wind MSDV (S,V) Layer-avg. mass-scalar flux divergence MSFC (V) Psuedo angular momentum (for cross sections) MTNG (V,LAT,LON, D,ST) Magnitude of tangential wind NORM (V) Normal component (for cross sections) PLAT (S) Latitude at each point (POL) PLON (S) Longitude at each point (POL) POIS (S, S) Solve Poisson equation of forcing function with boundary conditions POLF (S) Coriolis force at each point (POL) PVOR (V) Potential vorticity in a layer RELH (TMPC,DWPT) Relative humidity RICH (V) Richardson stability number in a layer ROSS (V1,V2) Rossby number SAVG (S) Average over whole grid SAVS (S) Average over subset grid SDIV (S,V) Flux divergence of a scalar SHR (V) Shearing deformation SM5S (S) 5-point smoother SM9S (S) 9-point smoother STAB (TMPC) Lapse rate over a layer in K/km STR (V) Stretching deformation TANG (V) Tangential component (for cross sections) TAV (S) Time average TDF (S) Time difference THAN (S) THTA field whose isentropes are rotated S degrees from the grid X axis. THTA (TMPC,PRES) Potential temperature THTE (PRES,TMPC, DWPC) Equivalent potential temperature TMWK (PRES, TMPK, RMIX) Equivalent potential temperature in Kelvin UN (V) North relative u component UR (V) Grid relative u component VN (V) North relative v component VOR (V) Vorticity VR (V) Grid relative v component XAV (S) Average along a grid row XSUM (S) Sum along a grid row YAV (S) Average along a grid column YSUM (S) Sum along a grid column VECTOR OUTPUT GRID AGE (S) Ageostrophic wind CIRC (V,S) Circulation (for cross section) DVDX (V) Partial x derivative of V DVDY (V) Partial y derivative of V GEO (S) Geostrophic wind GRAD (S) Gradient of a scalar INAD (V1,V2) Inertial advective wind ISAL (S) Isallobaric wind KCRS (V) K cross V KNTV (V) Convert meters/second to knots LTRN (S,V) Layer-averaged transport of a scalar NORMV (V) Vector normal wind (for cross sections) QVEC (S,V) Q-vector QVCL (S,V) Q-vector of a layer RAD (V,LAT,LON, D,ST) Radial wind ROT (angle,V) Coordinate rotation SMUL (S,V) Multiply a vector's components by a scalar SM5V (V) 5-point smoother SQUO (S,V) Vector division by a scalar TANGV (V) Vector tangential wind (for cross sections) THRM (S) Thermal wind over a layer TNG (V,LAT,LON, D,ST) Tangential wind VADD (V1,V2) Add the components of two vectors VASV (V1,V2) Vector component of V1 along V2 VAVG (V) Average vector over whole grid VAVS (V) Average vector over subset grid VECN (S1,S2) Create vector from north relative components VECR (S1,S2) Create vector from grid relative components VLAV (V) Layer average for a vector VLDF (V) Layer difference for a vector VMUL (V1,V2) Multiply the components of two vectors VQUO (V1,V2) Divide the components of two vectors VSUB (V1,V2) Subtract the components of two vectors WNAN (S) Hyperbolic wind field whose axis of dilatation is oriented S degrees from the grid X axis .
GPOINT GPOINT is the grid location to be used for the plot. The value can be entered in the following ways: 1. station numeric or character identifier 2. a latitude and longitude pair separated with a semicolon 3. @ followed by a grid x and y coordinate pair separated with a semicolon. If necessary, the grid data will be interpolated using a bilinear interpolation to the point specified. Examples: GPOINT = @1;1.5 Grid point (1,1.5) GPOINT = 30;-120 Grid point at 30 latitude and -120 longitude GPOINT = 5;5 Grid point at 5 latitude and 5 longitude. Note that this is probably an error and the input should have been @5;5 GPOINT = BWI Point located at Baltimore-Washington International Airport. .
GRDAREA GRDAREA specifies the area to be covered by the grid. This area is combined with PROJ to define the region over which the grid is evenly spaced. GRDAREA can be specified in three 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. If #GEOG is entered, the user's geographic table, GEOG.TBL, will be searched. A suffixed + or * will expand, and - will reduce the area. 3. STN This defines an area centered on a station found in the GEMPAK station table, which currently contains US, Canadian and Mexican stations. A suffixed + or * will expand, and - will reduce the area. Note that the other ways of specifying AREA are not valid for GRDAREA . For all projections, the lat/lon corners defined will be used exactly. For projections which include the pole, if lat1 = lat2 and lon1 = lon2, then lat1 will specify the range of data from the pole and lon1 will specify the central longitude. West longitude is negative. .
GRDLBL GRDLBL is the color number to be used in plotting the grid index numbers. If GRDLBL = 0 or blank, grid index numbers are not plotted. .
GRDNAM GRDNAM is the parameter name for the output grid. If this name is blank, the default name generated by the grid diagnostics package will be used. .
GUESS GUESS contains the information to use as a first guess for objective analysis programs. The name of the grid file containing the guess field and the time to be used to extract the field must be entered using ^ as a separator: guess file ^ grid time .
GVCORD GVCORD is the vertical coordinate of the grid to be selected. The standard values are: NONE for surface data PRES data in pressure coordinates (millibars) THTA data in isentropic coordinates (Kelvin) HGHT data in height coordinates (meters) The value in GVCORD may be overridden by specifying %GVCORD with the grids to be found. For example: GFUNC = SUB ( TMPC @850 %PRES, TMPC @1500 %HGHT ) will compute the difference between temperatures on the 850-mb level and the 1500-meter level. .
GVECT GVECT specifies a grid diagnostic function which yields a vector quantity. For more information, see the GPARM documentation. .
HILO HILO contains the information for plotting relative highs and lows in the following format: colorh;colorl/symbolh;symboll/rangeh;rangel/radius/counth;countl/interp Colorh and colorl are the colors for the high and low symbols to be plotted. If only a single number is entered, it will be used for both highs and lows. The default for this entry is 0. Symbolh and symboll specify the symbols to be plotted. The format for the symbol input is: character # precision where the character is the character to be plotted. If the character is an integer, markers corresponding to that number will be plotted. Information about markers can be found in the help for MARKER . The # is a flag to plot values beneath the marker. The integer following the # is the number of decimal places to display in the value. If a # is present without the following number, integer values are printed. The default for the symbols is 'H;L'. Rangeh and rangel are ranges for highs and lows specified as: minval - maxval where minval and maxval are integers which specify the range of values to be considered for designation as a high or low. The default is to consider all data. The search radius is the number of grid points to consider when searching for a relative minimum or maximum. The default is 3. Counth and countl are integer values for the maximum number of high and low values to return. The default is '20;20'. Interp is an interpolation flag which specifies whether the values and locations of the highs and lows will be at grid points, or will be interpolated between grid points. The default is 'NO'. In general, the above defaults are used if there is no entry for a part. For the parts which have values for both relative highs and lows, a single entry will be used for both highs and lows. .
HLSYM HLSYM defines the characteristics for the HILO symbols specified in HILO . The text sizes, value position, fonts, text widths and hardware/software flags are specified for the symbols (s) and plotted values (v) as: sizes;sizev/position/fonts;fontv/widths;widthv/hwflgs;hwflgv The size, font, width, and hw flag are entered as for TEXT entry. If only one value is given, it is used for both the symbol and value. The value plotting position may be 1, 2, or 3 where 2 is the default. The number selects the position of the value string beneath the symbol string. The three positions are shown below: H 1 2 3 Examples: HLSYM = 2;1/3/2//HW -- symbol text size = 2 value text size = 1 plot value in position 3 hardware text font 2 applies to both HLSYM = 2/1/1;2/ -- symbol text size = 2 value text size = 2 plot value in position 1 symbol text font = 1 value text font = 2 .
IDNTYP IDNTYP sets character or numeric station identifiers to be used for input or output. The valid values are STID and STNM. STID specifies station character identifiers; STNM specifies station numbers. If the value in IDNTYP is not STNM, the default of STID will be used. For example, to update station headers in SFSTNS: IDNTYP = STID -- compares character ids in file with those in the station table IDNTYP = STNM -- compares numeric ids in file with those in the station table .
INDXFL INDXFL is the name of the file which contains the GRIB message header information. If this parameter is left blank, the header information will be read from the GRIB data file specified in GBFILE . .
KXKY KXKY specifies the size of a grid as two numbers separated by a semicolon: kx ; ky These numbers are KX and KY, which represent the number of grid points in the x- and y- directions. If the projection is CED, these numbers may be DELTAX and DELTAY , the grid spacing in degrees in the x and y directions. If the spacing is input, the first character in KXKY must be #. For example: KXKY = #2.5;2.0 will create a grid with 2.5 degree spacing in x (longitude) and 2.0 degree spacing in y (latitude). .
LATLON LATLON specifies the latitude and longitude grid lines to be drawn. The line color, line type, line width, label frequency and increment are separated by slashes: color / line type / line width / x-freq;y-freq / x-increment;y-increment The label frequency specification contains the latitude and longitude label frequencies separated by a semicolon. The increment specification contains the latitude and longitude increments in degrees separated by a semicolon. If the color is 0 or LATLON is blank, grid lines are not drawn. The latitude and longitude increments will default to 10 degrees. The label frequency defaults to 1. Examples: LATLON = 1 Lat/lon grid lines are drawn every 10 degrees in color 1 using line type 1 and line width 1. LATLON = 4/8/3/2/5;5 Lat/lon grid lines are drawn every 5 degrees in color 4 using line type 8 and line width 3. Every other line is labelled. .
LEVELS LEVELS specifies the vertical levels to be extracted from the data set. The coordinate system for the levels is specified in the variable VCOORD as PRES, HGHT or THTA. LEVELS may be a list separated by semicolons. The following items may be included in the list: a single level; MAN for the mandatory levels below 100 mb; VAS for the standard VAS levels; a range of levels with an increment separated by - . The following items are also valid, provided they are not part of a list: ALL for all levels; a range of levels without an increment. SFC or 0 may be entered for surface data. TOP or -1 is the top level at the station. These values may not be entered for a range with an increment. .
LINE LINE is the color, line type, line width, and line label freqency separated by slashes. The individual values in each group are separated by semicolons: colr1;...;colrn/type1;...;typen/width1;...;widthn/labl1;...;labln For example: LINE = 1;2 / 7;8 / 4;5 / 2 assigns colors 1 and 2 to alternate lines, dashing patterns 7 and 8 to alternate lines, line widths 4 and 5 to alternate lines, and labels every other line. If any specification is missing, a default of 1 is used. If a color number of 0 is given, no plotting will be done. Information on color selection can be found in the help for COLORS . There are ten distinct line types: 1 - solid 2 - short dashed 3 - medium dashed 4 - long dash short dash 5 - long dash 6 - long dash three short dashes 7 - long dash dot 8 - long dash three dots 9 - medium dash dot 10 - dotted These patterns can be expanded or compressed by prefixing the single digit with a number from 1 to 9. A prefix of 1 compresses the pattern, 2 is the default and prefixes 3 -- 9 expand the basic pattern. For example, 32 expands line type 2 while 12 compresses the same pattern. If the line type is set to a single negative number, negative contour values will use the absolute value of the line type, and positive values will be solid. If the label information is a single number, n, then every nth line will be labelled. If a label is a sequence of numbers separated by semicolons, lines corresponding to positive integers will be labelled. The pattern established will be repeated to accommodate all lines. .
LSTALL LSTALL is a flag indicating whether the full contents of a file are to be listed. For example, in GDINFO, if LSTALL =YES, the grid identifiers will be listed; if LSTALL =NO, grid identifiers will not be listed. .
MAP MAP is the map color, line type and line width separated by slashes: map color / line type / line width If the color is 0, the map is not drawn. If the map color, line type, or line width is blank, a default of 1 is used. Additional help for colors is available in COLORS ; help on line types can be found in LINE . .
$MAPFIL $MAPFIL is the name of the map file to be used for maps drawn by GEMPAK programs. If no directory is specified, the GEMPLT map files in GEMMAPS will be used. The map files in GEMMAPS are named by concatenating the resolution, map boundaries, and area with the three-letter source file type. For example, the medium-resolution political world map from GSFC is called MEPOWO.GSF. RESOLUTION BOUNDARIES AREA SOURCE HIgh POlitical WOrld GSFc MEdium COastline NW quadrant WISconsin LOw REgional NE quadrant CIA CouNty SE quadrant SW quadrant WEst hemisphere North Hemisphere South Hemisphere US MarylanD The default map is $GEMMAPS/MEPOWO.GSF. The following map files are currently available: HICNMD.GSF MEPOWO.GSF LOCONH.GSF HICNUS.GSF LOCOSH.GSF HIPONE.GSF LOCOWO.GSF HIPONW.GSF HIPOSE.GSF HIPOSW.GSF HIPOWO.GSF HIPOWO.CIA HICOWO.CIA RIVERS.CIA LAKES.CIA ISLANDS.CIA TECTONIC.CIA The CIA map files were created from a subset of the CIA map database. .
MARKER MARKER specifies the marker color, type, size, line width and hardware/software flag separated by slashes: marker color / marker type / size / width / hw flag If the marker color is 0, no markers will be drawn. If the marker color is not specified, a default of 1 will be used. The marker type specifies the shape of the marker to be drawn. If the type is unspecified or zero, the current marker type (usually 1) will be used. The software marker types are: 1 plus sign 9 Z with bar 2 hexagon 10 Y 3 triangle 11 box with diagonals 4 box 12 asterisk 5 small X 13 X with top, bottom bars 6 diamond 14 star 7 up arrow 15 dot 8 X with top bar 16 large X Hardware marker types may differ. The marker size is a real number multiplier for the default marker size. If the size is zero or unspecified, the current size will be used. The hardware/software marker flag must be HW or SW. Otherwise, the current value is assumed. .
MAXGRD MAXGRD is the maximum number of grids that can be stored in the grid file being created. .
MIXRLN MIXRLN specifies the color, line type, line width, minimum, maximum, and increment for the background mixing ratio lines on thermodynamic diagrams: line color / line type / width / minimun / maximum / increment The values should be separated by slashes. If the color is 0, or MIXRLN is blank, no lines will be drawn. .
MRGDAT MRGDAT is a logical variable indicating whether sounding data is to be merged or unmerged. The type of unmerged data follows a slash: merge flag / unmerged data type The valid unmerged data types are: 1 = mandatory data below 100 mb ( TTAA ) 2 = mandatory and significant level data below 100 mb ( TTAA, TTBB, PPBB ) 3 = mandatory and significant level data below and above 100 mb ( TTAA, TTBB, PPBB, TTCC, TTDD, PPDD ) The default is 3. If the data is merged, the data type is ignored. When MRGDAT is used to create a sounding file, it indicates whether the file is to contain merged or unmerged data. Unmerged datasets will store the data as separate parts. Merged data sets contain values for each parameter at each level. If MRGDAT is used in a program to list data, the data will be merged if MRGDAT = YES. If MRGDAT = NO, the separate parts requested by the type will be listed. .
NPASS NPASS controls the number of passes for the Barnes objective analysis. Valid values are in the range 1 - 5. Note that two passes are STRONGLY RECOMMENDED. .
NTRACE NTRACE is the number of traces to be drawn in SFGRAM. If NTRACE is less than 5, the user input for TRACE x where x is greater than NTRACE will be ignored. The default value for NTRACE is 5. .
OUTPUT OUTPUT determines the output devices. The valid devices are the terminal (T) a file (F) or none (N). Specify the output devices desired by entering the appropriate letters with no separators. If output is sent to a file, the file name may be specified after a slash. If no file name is entered, the output will be written to "program.fil", where "program" is the name of the program being executed. If N appears anywhere in the output string other than in the file name, no output will be generated. Examples: OUTPUT = f / data.dat -- output will be written to data.dat OUTPUT = -- when no output device is specified, is sent to the terminal OUTPUT = tf -- output sent to the terminal and to the file program.fil where program is the GEMPAK program being run. .
PANEL PANEL specifies the panel location, panel outline color, line type and width separated with slashes: panel location / outline color / line type / width / region The panel location determines the location of the view region on the graphics device. It may be specified using a number or abbreviation as follows: NUMBER ABBREVIATION DESCRIPTION 0 ALL Entire device 1 UL Upper left quadrant 2 UR Upper right quadrant 3 LL Lower left quadrant 4 LR Lower right quadrant 5 L Left half 6 R Right half 7 T Top half 8 B Bottom half An easy 9-panel capability uses abbreviations M1,...,M9 which will be laid out on the page as: M1 M2 M3 M4 M5 M6 M7 M8 M9 Horizontal or vertical panels which divide the screen into thirds or fourths may be created using the syntax Tij where T is either V for vertical or H for horizontal, i is 3 for thirds or 4 for fourths, and j is the actual panel counting from the top or left. The view region may also be specified as four numbers separated with semicolons, giving the lower left and upper right corners in fractions of the graphics display area. The origin is in the lower left of the display. For example, the lower left quadrant can be given as: 0;0;.5;.5 If the panel location is unspecified, the current location is unchanged. The panel outline color, line type and line width specify the values used to draw a box around the specified region. The valid regions are VIEW, PLOT and DEVICE . If the color is 0 or unspecified, no box is drawn. .
POSN POSN is the position number to be used to plot data in GDMAP. If the position number is 0, the data will be plotted centered at the station. The position numbers are: 7 1 3 2 0 4 5 6 8 .
PROJ PROJ is the map projection, projection angles, and margins separated by slashes: map projection / angle1;angle2;angle3 / left;bottom;right;top (margins) For all map projections, the lower left and upper right corners of the graphics area should be specified in GAREA . The following simple map projections may be specified: MER Mercator NPS North Polar Stereographic SPS South Polar Stereographic LCC Northern Hemisphere Lambert Conic Conformal SCC Southern Hemisphere Lambert Conic Conformal CED Cylindrical Equidistant MCD Modified Cylindrical Equidistant UTM Universal Transverse Mercator NOR North Orthographic SOR South Orthographic The following full map projections may also be specified: MER (CYL) Mercator MCD (CYL) Modified Cylindrical Equidistant STR (AZM) Polar Stereographic AED (AZM) Azimuthal Equidistant ORT (AZM) Orthographic LEA (AZM) Lambert equal area GNO (AZM) Gnomonic LCC (CON) Northern Hemisphere Lambert Conic Conformal SCC (CON) Southern Hemisphere Lambert Conic Conformal UTM (OBM) Universal Transverse Mercator TVM (OBM) Transverse Mercator In addition, three angles MUST be specified in PROJ . The angles have the following meanings for the different projection classes: CYL The angles are not used. An appropriate value for angle2, polon, is used. AZM angle1 -- latitude of the projection's point of tangency angle2 -- longitude of the projection's point of tangency angle3 -- not used CON angle1 -- standard latitude 1 angle2 -- polon is the central longitude angle3 -- standard latitude 2 OBM angle1 -- tangential longitude angle2 -- not used angle3 -- not used The angles for the full map projection types are given as three numbers separated with semicolons. Note that THREE angles must be entered even if some angles are not used. There is a satellite projection available: SAT specifies McIDAS remapped or nonremapped navigation for a McIDAS area file specified in GAREA If the projection is DEF, the current map projection will be used. In the grid programs the following graph projections are also available: LIN linear x, linear y LOG linear x, logarithmic y KAP linear x, y ** KAPPA POL polar coordinates ( R, THETA ) Margins may be input as four numbers separated with semicolons. The four numbers represent the left, bottom, right, and top margin sizes in character widths. If no margins are specified, the default will be (0,3,0,0) in map mode and (6,4,4,1) in graph mode. If the input for the margins is NM, all four margins will be set to 0. .
PTYPE PTYPE is the type of y axis plot to be used, the height-to-width ratio of the plot, and the margins, separated by slashes. The valid inputs for type for the y axis are: LIN linear LOG logarithmic STUVE scaled by raising to KAPPA, 2/7, power KAP same as STUVE SKEWT logarithmic y-axis; skewed x-axis SKEW same as SKEWT If the height-to-width ratio is 0, the entire screen will be used. This is also the default when ratio is not specified. The margins are specified as: left;bottom;right;top. The values are multiples of the current character size. If the margin specification is missing or incomplete, a default appropriate to the program will be used. The default in the profile programs is: 10;3;(6 times wind barb size);5. The right margin allows room for plotting winds and typically has a value around 20. .
REFVEC REFVEC specifies the size and location on the screen of the reference arrow using the following format: Magnitude; x; y; text size/font/width/HW; string Magnitude refers to the size of the reference wind arrow to be plotted. For example, using 10.0 results in a reference arrow of 10.0 units being plotted. If the magnitude specified is 0, no reference arrow is plotted. The default is 0. The user specifies the location of the reference arrow by entering values between 0.0 and 1.0 for x-location and y- location. These values are normalized to the display so, for example, the center of the diplay is 0.5;0.5. If no values are entered, the reference arrow is plotted in the lower left hand corner: 0.05;0.05. The text attributes information is input as for the parameter TEXT . The text attributes: size, font, width and HW flag; are applied only to the text displayed with the reference vector. The label for the reference vector is the last input. This text may contain any keyboard character. If the string is empty, an appropriate label will be generated. .
REGION REGION specifies an areal location. In GPBOX, REGION may be VIEW, PLOT or DEVICE where: VIEW corresponds to the view region (includes margins); PLOT corresponds to the plot region (excludes margins); DEVICE corresponds to the entire device space. In OABOX, the region must be GRID, DATA, or EXTEND where: GRID corresponds to the area over which the objective analysis is performed; DATA corresponds to the area from which data will be extracted for the objective analysis; EXTEND corresponds to the extended grid area over which the first pass of the objective analysis is performed. .
$RESPOND $RESPOND is a logical variable indicating whether the user will respond interactively to GEMPAK programs. If set to NO, programs will not wait for input from the user. .
SAVFIL SAVFIL is the name of a file in which graphics from a graphics device can be saved. The graphics can only be saved on a device with readback capability. This file does not save graphics commands as they are executed. Rather, it saves a bitmap of the current graphics screen. GPSAVE can be used to create the file. GPREST displays a file stored using GPSAVE. The XW device driver currently has this capability. However, if the size of the graphics window is changed, the window during the restore must be exactly the same size. .
SCALE SCALE is the scaling factor for the data. All data will be multiplied by 10 ** SCALE . The user specifies the scaling factor for scalar grids and/or vector grids by entering: scalar / vector If SCALE is not specified, an appropriate scaling will be selected. In the grid programs, a data-dependent scaling will be selected. In the surface and sounding programs, a default of 0 will be used. If no vector scale is specified the scalar scaling factor will be used in its place. If the absolute value of SCALE is greater than 5 in a surface or sounding program, a value of 0 will be used. If the absolute value in a grid program is greater than 20, a default will be computed. Note that scaling data may create integer overflow problems in programs, such as SFMAP, which round data to the nearest integer. Valid integers must be in the range -2*10**9 to 2*10**9, approximately. .
SEARCH SEARCH controls the search radius in an objective analysis program. The radius is the maximum distance that a station may be from a grid point to be used in the analysis for that point. The search radius is set so that stations whose weighting factor is less than EXP (-SEARCH) are not used. SEARCH must have a value in the range 1 - 50. If the value is outside this range, a default value of 20 is used. If SEARCH is given a very small value, many grid points will not have three stations within the search area, and consequently will be set to the missing data value. SEARCH may also be used to set a flag to allow extrapolation of data values to grid points on the periphery of the data area. To do this, follow the value of SEARCH with /EX; for example, SEARCH = 20/EX will result in data extrapolation. .
SFEFIL SFEFIL is the name of the surface edit file to be used to update a surface file. SFEFIL is a text file which may be created using the program SFLIST with F as an output device. A text editor may be used to create or change the surface edit file. The parameters to be edited must be specified at the beginning of the surface edit file. For example: PARM = TMPF;DWPF Parameters that have character values, such as WTHR, cannot be edited. Instead, the numeric value must be used, e.g., WSYM in the case of WTHR. All the parameters which are to be edited must already exist in the surface data file, since no parameter transformations will be done. Station information, such as latitude, longitude and elevation, cannot be changed with SFEFIL . Use GEMPAK program, SFSTNS, to update station information in a surface file. The data follow the parameter list. Stations and times which do not already exist in the surface data file will be added. .
SFFILE SFFILE is the name of the surface data file to be accessed. .
SFOUTF SFOUTF is the output surface data file. SFOUTF is used in programs which create a new surface data file. It is also used in programs in which data is moved from an input file to an output file, in which case, SFFILE is the original file. .
SFPARM SFPARM is a list of surface parameters to be used in a surface program. The four-character parameter names must be separated by semicolons. For example: SFPARM = TMPF;DWPF;WTHR 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, relative humidity can be computed from the temperature and dewpoint temperature. Note that STHA, STHE, and SMXR are computed from PALT. 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: 7 1 9 3 2 0 4 5 10 6 8 In the example above, WTHR is plotted in position 3. Functions can be used to modify/qualify the output parameters. These functions must follow the parameter name and are applied in the order given; however, arithmetic operators must precede the other operators. The function symbols must precede the qualifying value and are defined as follows: * multiply = equal to / divide $ direction + add < less than - subtract > greater than In the case of weather symbols, the size, line width and other information needed to draw 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. For all the symbols, the information is entered as :size:width; for arrows and barbs the information is entered as :size:width:type:headsiz, where the headsiz applies only to arrows. 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 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. For example, if TYPE=132, a barb will be plotted as a circle if the wind is calm; it will begin on the edge of the cloud cover symbol, and 50-unit flags will be filled. The default is 111 unless sky symbols are being plotted in which case it is 131. The GEMPAK surface parameters and the corresponding four-character abbrevations are: TEMPERATURE TMPC - temperature in Celsius TEMP - temperature in Celsius (alternate name) TMPF - temperature in Fahrenheit TMPK - temperature in Kelvin STHA - surface potential temperature in Kelvin STHE - surface equivalent potential temperature in Kelvin STHK - surface equivalent potential temperature in Kelvin STHS - surface saturation equiv. pot. temp. in Kelvin TVRK - virtual temperature in Kelvin TVRC - virtual temperature in Celsius TVRF - virtual temperature in Fahrenheit THTV - virtual potential temperature in Kelvin TMAX - maximum 24-hour temperature in Celsius TMIN - minimum 24-hour temperature in Celsius SSTC - sea surface temperature in Celsius LTMP - temperature of surface air lifted to 500 or !x mb MOISTURE DWPC - dewpoint in Celsius DWPT - dewpoint in Celsius (alternate name) DWPF - dewpoint in Fahrenheit DWPK - dewpoint in Kelvin DPDC - dewpoint depression Celsius DPDF - dewpoint depression Fahrenheit DPDK - dewpoint depression Kelvin SMXR - surface mixing ratio in g/kg SMXS - surface saturated mixing ratio in g/kg RELH - relative humidity in percent TMWK - wet bulb temperature Kelvin TMWC - wet bulb temperature Celsius TMWF - wet bulb temperature Fahrenheit VAPR - vapor pressure in millibars VAPS - saturation vapor pressure in millibars PRESSURE AND ALTIMETER PMSL - mean sea level pressure in millibars PALT - pressure in millibars from altimeter ALTI - altimeter setting in inches of mercury ALTM - altimeter setting converted to millibars SALT - abbreviated altimeter in millibars SMSL - abbreviated mean sea level pressure SALI - abbreviated ALTI RMSL - first 3 digits left of decimal of PMSL * 10 RSLI - first 3 digits left of decimal of ALTI * 100 RSLT - first 3 digits left of decimal of ALTM * 10 PTND - complete pressure tendency plotting number PTSY - pressure tendency symbol number P03C - pressure change over 3 hours ZMSL - estimated height at PMSL Z000 - estimated height at 1000 mb Z850 - estimated height at 850 mb Z800 - estimated height at 800 mb WIND 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 GUST - wind gusts in knots GUMS - wind gusts in meters/second SYMBOLS In the appropriate graphics programs, use the following to display symbols: ARRK - wind arrow (knots) ARRM - wind arrow (m/s) ARRW - wind arrow (m/s) BARB - wind barb (m/s) BRBK - wind barb (knots) BRBM - wind barb (m/s) DARR - wind arrows of uniform length CSYL - low cloud type CSYM - middle cloud type CSYH - high cloud type CSYT - cloud type on first reported level PTND - complete pressure tendency with symbol PTSY - pressure tendency symbol only PWTH - past weather SKYC - sky coverage SKYK - sky coverage with wind barbs in knots SKYM - sky coverage with wind barbs in m/s WSYM - present weather CLOUD For the following parameters, the character x may be replaced by L, M, or H, indicating low, middle or high clouds. The character T indicates the value of the parameter at the level of maximum cloud coverage. xCLD - character cloud coverage TCLD - character maximum cloud coverage xCLO - fractional cloud coverage TCLO - fractional maximum cloud coverage CLCx - numeric cloud coverage CLCT - numeric maximum cloud cover CLDS - combined cloud coverage from three levels CMBC - numeric combined cloud coverage from three levels CLHx - cloud height in hundreds of feet CLDx - combined cloud height and coverage CLDT - maximum value of CLDx COMx - numeric combined cloud height and coverage COMT - maximum value of COMx For the next two cloud parameters the x can be replaced by 1, 2, or 3 and represents the cloud report number. CHCx - numeric combined cloud height and coverage CHDx - combined cloud height and short code The following numeric cloud parameters are WMO standard codes. CFRT - fraction of celestial dome covered by cloud from WMO Code 2700 CLFR - fraction of celestial dome covered by low or mid clouds from WMO Code 2700 CTYL - low-level cloud genera from WMO Code 0513 CTYM - mid-level cloud genera from WMO Code 0513 CTYH - high-level cloud genera from WMO Code 0513 CBAS - Cloud base height from WMO Code 1000 WEATHER WTHR - character weather code from any numeric code WCOD - character weather code WNUM - numeric weather code W604 - numeric weather code from the 604 file WSYM - weather symbol number WTMO - character weather code from WMO WWMO - numeric WMO weather code WASH - Asheville surface data weather code RWSH - numeric Asheville surface data weather code PWTH - character past weather in WMO code PWWM - numeric past weather in WMO code 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 MISCELLANEOUS DDEN - density of dry air in kg/(m**3) VSBY - visibility in statute miles VSBK - visibility in kilometers PnnI - precipitation over last nn hours in inches nn = 03, 06, 09, 12, 18 or 24 PnnM - precipitation over last nn hours in millimeters nn = 03, 06, 09, 12, 18 or 24 SNOW - snow depth in inches HAIL - hail flag HLSZ - hail size in centimeters WHGT - wave height in meters WPER - wave period in seconds HEAT - heat index in Fahrenheit HMTR - humiture (apparent temperature) in Fahrenheit WCEQ - wind chill equivalent temperature in Fahrenheit SPACING SPAC - plot a space, accounted for in FILTER BLNK - plot a blank, not accounted for in FILTER .
SFPRMF SFPRMF specifies the packing information for the surface file to be created. It may be the name of a surface parameter packing file or the information itself entered as follows: SFPRMF=PRM1/MIN1-MAX1-RES1;PRM2/MIN2-MAX2-RES2; ... where each PRMi, MINi, MAXi, and RESi is the parameter name, minimum, maximum and resolution for a parameter to be included in the file. If SFPRMF specifies a file name, then each line of the file must contain the following information separated by blanks or tabs: parameter name CHAR*4 minimum data value REAL maximum data value REAL resolution REAL The resolution should be an integral power of 10; otherwise the next smaller resolution will be used. For example, res = .5 will become .1. If the data are not to be packed, the minimum and maximum data values and the resolution should not be included. Note that either all of the parameters or none of them must have packing information. $GEMTBL/SF51.PACK is a typical table used to pack surface data. This file may be used as an example when creating a packing file. .
SHIPFL SHIPFL is a logical variable which indicates whether the surface file contains stations which are not at a fixed location, such as moving ships, aircraft, or floating buoys. A ship file will store and write data differently from a standard GEMPAK surface file. However, these files can be read using the surface library and all programs which access data in surface files can be used unchanged. Note that station information cannot be added to these files, since the station information must be stored with the data. .
SKIP SKIP is a variable which determines the contour points or plot points to skip. Input is entered as: skip_contour / skip_plot_x ; skip_plot_y The defaults for skip_contour and skip_plot are 0. Skip_contour thins the input grid before computing the contours to be drawn. Skip_plot_x and _y specify the points at which data is to be displayed. If skip_plot_x is positive and skip_plot_y is not specified, skip_plot_y is set to skip_plot_x. If skip_plot_x is negative, the x plot locations on alternate rows are indented by half the skip_plot_x value. In this case, the absolute value of skip_plot_x must be odd. If not, the absolute value minus 1 is used. If no value for skip_plot_y is specified, half the skip_plot_x value is used. Examples: SKIP SKIP_CNTR SKIP_PLOT_X SKIP_PLOT_Y STAGGER ' ' 0 0 0 no 2 2 0 0 no -1 0 0 0 no 2;3 2 0 0 no /3 0 3 3 no /2;3 0 2 3 no /;1 0 0 1 no /-1 0 1 0 yes /-3 0 3 1 yes /-1;1 0 1 1 yes .
SKPMIS SKPMIS is a logical variable which indicates whether non-reporting stations will be listed. If SKPMIS is YES, nonreporting stations will not be listed. Otherwise, all stations will be listed. In SFMAP, markers can be plotted at nonreporting stations when SKPMIS is NO. .
SNEFIL SNEFIL is the name of the sounding edit file to be used to update a sounding data file. SNEFIL is a text file which may be created using the program SNLIST with F as an output device. A text editor may be used to create or change the edit file. The parameters to be edited must be specified at the beginning of the edit file. For example: SNPARM = PRES;TMPF;DWPF If the output sounding file exists, the data set parameters must be the same as those listed in the edit file. Station information, such as latitude, longitude, and elevation, cannot be changed with SNEFIL . Use GEMPAK program SNSTNS to update station information in a sounding file. If the file does not exist, a new, unpacked file with these parameters will be created. The data follows the parameter list. Only level data will be added to the file. Stability indices from STNDEX will be ignored. Stations and times which do not already exist in the surface data file will be added. .
SNFILE SNFILE is the filename for an upper air data set. .
SNOUTF SNOUTF is the output sounding data file. SNOUTF is used in programs which create a new sounding data file. It is also used in programs in which data is moved from an input file to an output file, in which case SNFILE is the original file. .
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: 7 1 9 3 2 0 4 5 10 6 8 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 > greater than 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 Calm winds are plotted as a circle or an arrowhead for barbs and arrows, respectively. Arrowheads and 50-unit barb flags are filled. 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. The following page lists the GEMPAK sounding parameters and the corresponding four-character abbrevations. TEMPERATURES TMPC - temperature in Celsius TEMP - temperature in Celsius (alternate name) 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 DWPT - dewpoint in Celsius (alternate name) DWPF - dewpoint in Fahrenheit DWPK - dewpoint in Kelvin DPDC - dewpoint depression Celsius DPDF - dewpoint depression Fahrenheit DPDK - dewpoint depression Kelvin MIXR - mixing ratio in g/kg MIXS - saturation mixing ratio in g/kg PWTR - precipitable water in mm RELH - relative humidity in percent TMWK - wet bulb temperature Kelvin TMWC - wet bulb temperature Celsius TMWF - wet bulb temperature 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 dekameters 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 ARRK - wind arrow (knots) ARRM - wind arrow (m/s) ARRW - wind arrow (m/s) BARB - wind barb (m/s) BRBK - wind barb (knots) BRBM - wind barb (m/s) 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) 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) CINS - Convective Inhibition (500 m) EQLV - Equilibrium Level LFCV - Level of Free Convection BRCH - Bulk Richardson Number (500 m, 6000 m) 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 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 PWTR - precipitable water (mm) up to the specified level SPACING SPAC - plot a space, accounted for in FILTER BLNK - plot a blank, not accounted for in FILTER .
SNPRMF SNPRMF specifies the packing formation for the sounding file to be created. It may be the name of a sounding parameter packing file or the information itself entered as follows: SNPRMF = PRM1/MIN1-MAX1-RES1;PRM2/MIN2-MAX2-RES2; ... where each PRMi, MINi, MAXi, and RESi is the parameter name, minimum, maximum and resolution for a parameter to be included in the file. If SNPRMF specifies a file name, then each line of the file must contain the following information separated by blanks or tabs: parameter name CHAR*4 minimum data value REAL maximum data value REAL resolution REAL The resolution should be an integral power of 10; otherwise the next smaller resolution will be used ( e.g., res = .5 will become .1). If the data are not to be packed, the minimum and maximum data values and the resolution should not be included. Note that either all of the parameters or none of them must have packing information. It is important to remember to include the vertical coordinate in the parameter packing list. $GEMTBL/SNPACK.TBL is a typical table used to pack sounding data. This file may be used as an example when creating a packing file. Note that if MRGDAT is NO, the data will be packed using the standard packing for unmerged data, and the value of SNPRMF will be ignored. .
SOURCE SOURCE indicates whether the data used to compute the average station spacing are to be read from a surface or sounding file. Use SF to read from a surface file and SN to read from a sounding file. .
STATION STATION is the station to use in SFGRAM. Either a station character identifier or station number may be entered. If a single station is entered, all traces will use data from that station. If a list of stations is entered, trace 1 will be for station 1, trace 2 for station 2, ... Stations in the list must be separated using semicolons. .
STNCOL STNCOL specifies the color for the station identifier, time and the parameters specified in STNDEX . These parameters are written at the top of the plot. .
STNDEX STNDEX is the list of stability indices or station parameters for upper-air data. The items in the list must be separated using semicolons. The depth for the layer averages may be specified preceded by a ! in the user input. For example, BRCH!1000!8000 instructs the program to average over a mixed layer 1000 meters deep and lower tropospheric layer 8000 meters deep. Similarly MLTH!750 results in an average potential temperature over a mixed layer 750 meters deep while the default is 500 meters. The following is a list of valid names: SHOW Showalter index LIFT Lifted index SWET SWEAT index KINX K index CTOT Cross totals index VTOT Vertical totals index TOTL Total totals index CAPE Convective Available Potential Energy CINS Convective Inhibition EQLV Equilibrium Level LFCV Level of Free Convection BRCH Bulk Richardson Number LCLT Temperature in Kelvin of the LCL LCLP Pressure in millibars of the LCL MLTH Mean mixed layer potential temperature MLMR Mean mixed layer mixing ratio STID Station identifier STNM Station number SLAT Station latitude SLON Station longitude SELV Station elevation .
STNFIL STNFIL is the name of a file which contains station information which includes the character identifier, number, name, state, country, latitude, longitude and elevation for each station. All this information, except the station name, is stored as station header information in surface and sounding data files. The file $GEMTBL/SFSTNS.TBL is a surface station table containing US, Canadian and Mexican stations. $GEMTBL/SNSTNS.TBL is an upper-air table for the Northwest quadrant. Information in the files must be stored using the exact format used in current tables, since they are read with a FORTRAN FORMAT statement. They may be changed using a text editor. WARNING: The variable STNFIL is used for both surface and upper-air programs. Care should be taken that the correct file is specified. .
TAXIS TAXIS contains the range, increment and location for labels on a time axis input as: START-STOP-INC;LB;GL;TM START and STOP are GEMPAK date/times which may be abbreviated. If the values are omitted, the data range will be used. The time axis will be reversed if the TAXIS specification begins with R or if the times are input with a later time first. INC is the time increment in hours and minutes. The form for INC is HHHMM. If one or two digits are entered, hours will be assumed. If INC is omitted, a default appropriate for the range will be used. If the time range exceeds 720 days, the increment is ignored, and an appropriate labelling interval is selected automatically. LB, GL, and TM are the frequencies for labels, grid lines, and tick marks. Examples: 5/12-6/18-6 Draw the axis from 5/12 to 6/18 with labels at 6-hour increments. 17/12-20/12-3;2;4;1 Draw the axis from 17/12 to 20/12 with labels at 6-hour increments, grid lines at 12-hour increments, and tic marks at at 3-hour increments. .
TEXT TEXT is the size, font, text width and hardware/software flag for graphics text separated with slashes: text size / font / width / hw flag The size is a real number multiplier for the default text size. If the size is zero or unspecified, the current size will be used. The text width is the integer line width to be used in generating software text. If the text size, font or width is not specified, the current value is used. The hardware/software selector must be HW or SW to change to hardware- or software-generated text. The font number must be specified by using the HW selector and choosing a font number from the list below. REGULAR ITALIC BOLD ITALIC-BOLD Courier 1 11 21 31 Helvetica 2 12 22 32 Times 3 13 23 33 Examples: TEXT = 1/2//HW -- text size = 1, hardware text font 2 TEXT = 2.5 -- text size = 2.5, current text font .
THTALN THTALN specifies the color, line type, line width, minimum, maximum, and increment for the background dry adiabats (potential temperature lines) on thermodynamic diagrams: line color / line type / width / minimun / maximum / increment The values should be separated by slashes. If THTALN is blank, no lines will be drawn. .
THTELN THTELN specifies the color, line type, line width, minimum, maximum, and increment for the background moist adiabats (equivalent potential temperature lines) on thermodynamic diagrams: line color / line type / width / minimun / maximum / increment The values must be separated by slashes. If THTELN is blank, no lines will be drawn. .
TIMSTN TIMSTN contains the maximum number of times to include in a file and the number of stations to be included in addition to the stations in STNFIL . .
TITLE TITLE is the title color, title line, and title string separated by slashes: title color / title line location / title string | short title If the title color is 0, a title is not plotted. The title line specifies the line on which the title will be written. The value of the title line has the following meanings: 0 bottom line -n n lines from bottom +n n lines from top If the line is not specified, the default is program dependent. The title string is the title to be written. If no title string is specified, a default title will be determined by the program. In the grid display programs, special characters will be replaced as follows: ^ Forecast date/time ~ Valid date/time @ Vertical level _ Grid function $ Nonzero scaling factor # Grid point location If the information for which a character stands is not applicable to the program, nothing is output in its place. Zero values of the scaling factor are not displayed. A short title may also be input by the user after a |. This is used to label the metafile frame in the NC device driver. If the short title is blank, a suitable label is generated for the frame. .
TRACE TRACE parameters contain specifications for each trace on the meteogram in the following format: parameters/colors/range/witnes!parameters/colors/range/witnes The parameters before the ! will be plotted on the left of the plot; those after the ! will be plotted on the right. The parameters may be any GEMPAK surface parameter. Real-valued parameters will be drawn as a graph. Character valued parameters will be rotated 90 degrees and written on the plot. Symbol parameters will be drawn as symbols. For GUST and GUMS, the character G will be plotted. Up to four parameters may be plotted along each axis. The parameters must be separated using semicolons. Character and weather symbol data may only be plotted in positions 1, 2 or 3. Each parameter name may be followed by a colon, the size or line type, a second colon and the width. For example, WSYM:.5:5 will draw weather symbols half the default size with a line width of 5. For example, TMPF:3 will plot a temperature line using dash pattern 3. The colors for the parameters must also be separated using semicolons. If a single number is entered, all parameters are drawn in that color. If a zero is entered, the current default color is used. The range specifies the scaling of the y axis. The format is: start;stop;increment. Note that in this program, the parts of range must be separated using semicolons. If no range is given, it is selected using the data values. Witness lines are specified in WITNES. These are horizontal dotted lines. A list of y values may be entered separated by semicolons. If the value of witnes is YES, a witness line will be centered on the plot. .
VCOORD VCOORD specifies the vertical coordinate system of the levels to process. Currently, there are four coordinates: NONE = surface data only PRES = pressure THTA = theta (isentropic) HGHT = height A list or range of levels will be based on the vertical coordinate type, with the exception of MAN or VAS which always refer to a pressure coordinate system. Note that data are ignored within superadiabatic layers found working upwards from the surface when interpolations are performed to isentropic coordinates. .
WIND WIND specifies the wind symbol, size, width, type, and head size separated by slashes: wind symbol / size / width / type / arrow head size The wind symbol contains a letter for symbol type, a letter for symbol units and a color number with no separators. The character meanings are: TYPE: B = BARB A = ARROW UNITS: K = KNOTS M = m/s, with N = m/s, with no reference arrow reference arrow COLOR: Color number 0 = no wind plotted The default is BM1, i.e., barbs in meters/sec plotted in color number 1. If a partial specification is given, the remaining characteristics will be taken from the default. The wind size is a real number which will be used as a multiplier for the default wind symbol size. If this number is negative, zero, or missing, the current size will be used. The sizes for barbs and arrows are independent. The width is an integer specifying the line width to use in drawing the arrows or barbs. 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 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. For example, if TYPE=132, a barb will be plotted as a circle if the wind is calm; it will begin on the edge of the cloud cover symbol, and 50-unit flags will be filled. The default is 111. The head size is a real valued multiplier used for the length of the arrow head. This variable is not used for wind barbs. .
WINPOS WINPOS specifies the position for plotting winds. Up to three separate wind profiles may be plotted. The stability indices will also be positioned at the top of the plot according to WINPOS . Position 1 is the leftmost position. The value of WINPOS will be incremented modulo 3 until the screen is cleared or the program is run again. .
XAXIS XAXIS contains the left bound, right bound, label increment, and frequency information separated by slashes in the form: left/right/increment/lbfq;gdfq;tkfq The frequencies for labels, grid lines, and tick marks follow the last slash and are separated with semicolons. Appropriate defaults are provided if values are not specified. If the increment is positive, all the label values will be divisible by the increment. If it is negative, the label values will begin with the left value and be separated by the increment. The bounds and increment are for the scaled data. .
YAXIS YAXIS contains the lower bound, upper bound, label increment, and frequency information separated by slashes in the form: lower/upper/increment/lbfq;gdfq;tkfq The frequencies for labels, grid lines, and tick marks follow the last slash and are separated with semicolons. If the increment is positive, all the label values will be divisible by the increment. If it is negative, the label values will begin with the lower value and be separated by the increment. The bounds and increment are for the scaled data. Defaults will be supplied if no specification is given. The following defaults will be used when appropriate: vcoord lower upper defaults ------ ----- ----- ---------------- PRES 1020 100 Mandatory levels THTA 270 400 10 HGHT 0 20000 1000