SFCCALC
Sections
NAME
sfccalc - Surface data contouring program
SYNOPSIS
sfccalc [parameters...] filename
PARAMETERS
| Command Line | Resource | Default | Description |
| -h | help | No | Lists basic help information. |
| -df=filename | default | .wxpdef | Sets the name of the resource file. |
| -na=name | name | sfccalc | Specifies the name used in resource file parsing. |
| -ba | batch | No | Run program in batch mode |
| -me=level | message | out2 | Specifies level of messages to be displayed
|
| -fp=filepath | file_path | current directory | Specifies location of database files. |
| -dp=datapath | data_path | current directory | Specifies the location (path) of the input raw data files. This may be modified in the name convention file. |
| -cp=conpath | con_path | current directory | Specifies the location (path) of the input surface converted data files. This may be modified in the name convention file. |
| -rp=rawpath | raw_path | current directory | Specifies the location of the output raw files generated by the program. These files will not be generated unless the out_file resource is specified and the output is plotted data. |
| -gp=gridpath | grid_path | current directory | Specifies the location of the output grid files generated by the program. These files are not generated unless the out_file resource is specified and the output is a gridded field. |
| -ip=imagepath | image_path | current directory | Specifies the default location of the output GIF images generated by the program. |
| -nc=name_conv | name_conv | name_conv | The name convention file specifies how files are named in WXP. This sets which name convention file to use. |
| -if=in_file | in_file | sfc_cvt | Specifies the input file name tag. The default is sfc_cvt, but it can be modified to any value in the filename convention file. A full name convention can be specified as well. |
| -of=out_file[,out...] | out_file | None | Specifies what type of raw or grid file to create. By default, no output
file is generated when the program is run. To produce an output file, this resource
must be specified. There are the following output file types:
Second, the out_file resource specifies the output file name tag. The default is
sfc_raw or sfc_grd but it can be modified to any value in the filename
convention file. The file name tag can be specified separately or appended to the file
type: A full filename can be specified which can contain name convention tags. |
| -pf=file_param | file_param | User prompt Batch: use |
This specifies how to treat output files that exist:
|
| -cf=cityfile | city_file | sao.cty | Specifies the name of the city database file used in finding station locations. |
| -mf=mapfile[,...] | map_file | wxp.map or cont.dat, country.dat for domains outside North America |
Specifies the name of the map database file. Multiple maps can be specified along with attributes to describe how to draw the map. |
| -cu=[hour|la] | current | None | This specifies to use current data files. The current filename is based on the name convention. An optional hour can be specified for older data. If la is specified, the program will search back to find the most recent available file. |
| -ho=hour | hour | None | This resource specifies the exact hour that a data file is valid for. This locks in the start hour for a multi-file sequence. |
| -nh=num_hour | num_hour | 0 (no loop) | This specifies the number of hours that will be used in the plot. If this is not specified, a single hourly plot will appear. If this is specified, a loop of plots over this time will be generated. |
| -id=identifier | identifier | None | Used to plot a specific observation. If not specified, all stations will be plotted. |
| -pd=domain | plot_domain | User prompt Batch: first domain in wxp.reg file. |
This specifies the plotting domain. The projection, aspect ratio and the domain size are specified. |
| -gd=grid_domain | grid_domain | Same as plot domain | This specifies the domain to use when fitting data to a grid. If this is not specified, it is the plot_domain. |
| -re=region | region | Same as plot domain | This resource is synonymous with the plot_domain. |
| -pr=prior | stat_prior | Depends on domain size | This specifies the lowest priority to use in the plot. Priorities range from 1 to 7. |
| -va=variable | variable | User prompt Batch: first variable listed in the sfccalc.var file |
This specifies the variable to plot along with its formatting attributes. Multiple variables can be specified separated by commas for overlay plots. A list of valid variables is given below. |
| -oa=smooth[,radinf] [,passes] [,converg] [,min_sta] | object_param | 1,3,1,.2,1 | Specifies the objective analysis parameters. There are 5 parameters including smoothing, radius of influence, number of passes, convergence parameter and minimum number of stations. |
| -pl=plot_type | plot_type | User prompt Batch: fill contours or vectors |
Specifies the type of output plot. By default, the user is prompted for
the plot type. To produce a contour or vector plot, use the following plot types: Contours:
Vectors:
|
| -sc=scale_factor | plot_scale | 1.0 | Specifies a scaling factor for all plotted text, symbols, vectors, etc. |
| -fm=format | plot_format | None | Specifies the output format of the plots. This is generally used to specify how many decimal places get displayed on the plot and in the output raw files. |
| -pp=param[,param...] | plot_param | None | Specifies additional plotting parameters. See the plot_param resource for more details. |
| -dr=drawable[,...] | draw | all | Specifies which part of the plot is to be drawn. |
| -la=label[,...] | label | Program defaults | Specifies the labels to be plotted around the plot. By default, labels are generated by the program and plotted above and below the plot. This resource overrides these labels. |
| -in=interval | con_interval | None for plots, User prompt for grids. Batch: 0 | Specifies the contour interval to use in contouring grids. This can also be used to color code plotted data and vectors. |
| -cb=base | con_base | Lowest contour value, maximum wind speed | Specifies the base value for color fill contours, and wind speed per grid distance. For more details, see the con_base resource. |
| -fl=font_list | font_list | modern.fnt | Specifies a list of fonts to use in the plots. |
| -ct=color_table | color_table | wxp.clr | Specifies the color table to use in the plot. This maps color names to actual RGB color values. |
| -cot=color[:attr] | color_text | white black for inverse plots. |
Specifies the text color for labels above and below the plot. |
| -cod=color[:attr] | color_data | green | Specifies the color for plotted data. |
| -com=color[:attr] | color_map | red | Specifies the color for background maps. |
| -coln=color[:attr] | color_line | magenta:st=dsh | Specifies the color for lat/lon lines. |
| -cowd=color[:attr] | color_wind | white black for inverse plots. |
Specifies the color for wind barbs. |
| -cocd=color[:attr] | color_cloud | white black for inverse plots. |
Specifies the color for cloud cover symbols. |
| -cowx=color[:attr] | color_wx | yellow brown for inverse plots |
Specifies the color for weather symbols |
| -cocm=color[:attr] | color_cmap | black | Specifies the color for color fill contour maps. |
| -coco=color[:attr] | color_cont | white black for inverse plots. |
Specifies the color for line contours. |
| -cof=[val:]color[:attr],... | color_fill | A predefined color set based on the wxp.clr color table | Specifies the color fill contour color set. See the color_fill resource for more details. |
| -cola=color[:attr] | color_label | white black for inverse plots. |
Specifies the line contour label color. |
| -cocl=color[:attr] | color_clabel | black | Specifies the color fill contour label color. |
| -de=device[,...] | device | User prompt Batch: display |
Specifies the output device. |
| -ti=title | title | Program name | Specifies the window title. |
| -ic | icon | Off | Specifies whether to open window in iconified mode. |
| -bg=color | background | black white for inverse plots |
Specifies the background color of the window. |
| -ge=geometry | geometry | 640x480 | Specifies the window and paper geometry. |
| filename[#seq] [filename[#seq]...] |
filename | None User Pompt Batch: current=la |
The name of the surface converted data file to be plotted. An optional sequence number can be added to designate the time for non-WXP files. More than one file can be specified to generate a loop. |
DESCRIPTION
This program contours surface data on a background map. The input to the program is a surface converted file produced by either the sacvt or smcvt programs. Then, based on a plot domain and a variable selected by the user, a plot is generated. Overlay plots, plots and loops can also be generated if the appropriate options are set.
The programs starts off by prompting the user for input converted file name. The user may specify the input file either via the command line of through the current resource. The input naming convention is specified by the sfc_cvt tag but this can be changed with the in_file resource. To generate a loop, the num_hour resource can be specified. This will tell the program to loop through this number of hours.
Next, the program prompts the user for the plot domain. This is done through a region menu which has predefined regions available. If needed a full plot domain can be specified to get a precise domain. The domain can be interactively changed using the mouse once the plot has been generated.
After the region has been set, the city database is read in and a cross-reference table is setup. Since converted data is not saved with location information, the program will refer to this table to location each station in the input file.
The program will now prompt the user for the particular output variable to plot. The program will show a menu of commonly used variables but many more are defined internally by the program and in the sfccalc.var file. The internal variables are:
| Variable | Description and units | Plots |
| city | All stations in the data file | string |
| temp | Temperature (F) | value |
| ttd | Temperature and dewpoint (F) | value0=temp, value1=dewp |
| dewp | Dewpoint (F) | value |
| dewd | Dewpoint depression (F) | value |
| wdir | Wind direction (deg) | value |
| wspd | Wind speed (knt) | value |
| wgst | Wind gust (knt) | value |
| wbrbc wbrb wind |
Wind speed and direction (knt) | value0=dir, value1=spd |
| uwnd | U wind component - EW relative (m/s) | value |
| vwnd | V wind component - NS relative (m/s) | value |
| uwndg | U wind component - grid relative (m/s) | value |
| vwndg | V wind component - grid relative (m/s) | value |
| alt | Altimeter setting (in_Hg) | value |
| pres | Sea level pressure (mb) use level parameter to get station/surface pressure | value |
| pralt | Sea level pressure or altimeter setting if sea level pressure is missing (mb) | value |
| elev | Station elevation (m) | value |
| wx | Present weather (SAO string) | string |
| vis | Visibility (mi) | value, formatted string |
| cldcl | Cloud ceiling (100 ft) | value, formatted string |
| cldclc | Cloud ceiling code (from synoptic code 0-9) | value |
| cldcv | Cloud cover (cloud string) | value=%, string |
| ptend | Pressure tendency (mb, trend is a string) | value, string=trend code |
| prec | Precipitation (in) use time parameter to specify which type (3,6,12,24 hour) | value |
| extt | Extreme temperature (F) uses maximum if available, else minimum | value |
| maxt | Maximum temperature (F) use time parameter to specify which type (6,24 hour) | value |
| mint | Minimum temperature (F) use time parameter to specify which type (6,24 hour) | value |
| snwdp | Snow depth (in) | value |
| nlcld | Amount of low clouds (code string) | value=%, string=code |
| lcld | Low cloud type (string) | string |
| mcld | Middle cloud type (string) | string |
| hcld | High cloud type (string) | string |
| solar | Equivalent solar radiation (min) | value |
| sst | Sea surface temperature (C) | value |
| wavper | Wave period (sec) | value |
| wavhgt | Wave height (m) | value |
| vpres | Vapor pressure (mb) | value |
| svpres | Saturation vapor pressure (mb) | value |
| wchilt | Wind chill temperature (K) | value |
| wchilf | Wind chill factor (W/m^2) | value |
| heat | Heat index (K) | value |
| humit | Humiture (F) | value |
| mrat | Mixing ratio (g/kg) | value |
| smrat | Saturation mixing ration (g/kg) | value |
| shum | Specific humidity (g/kg) | value |
| rhum | Relative humidity (%) | value |
| wetblb | Wetbulb temperature (K) | value |
| thetaw | Wetbulb potential temperature (K) | value |
| thetae | Equivalent potential temperature (K) | value |
| thetav | Virtual potential temperature (K) | value |
| theta | Potential temperature (K) | value |
| vtemp | Virtual temperature (K) | value |
| fr | Flight rules (number and string: 0=VFR, 1=MVFR, 2=IFR) | value=0, string=VFR value=1, string=MVFR value=2, string=IFR |
| front | Fronts (special plot type) |
These parameters can be accessed by name if they have not been redefined in the sfccalc.var
file. Otherwise, prepending a "+" to the variable name will guarantee
these variables will appear. Also, time can be specified for use with precipitation (anal-6acc::prec::%.2f
with give 6 hour precipitation).
There are several derived variables from this list which are defined in the sfccalc.var file. These include composite plots, overlay plots and computed grids.
| Variable | Description | Plots |
| wind | A vector quantity of <uwndg,vwndg> | vector |
| vect | Wind vector plot | vector |
| strm | Streamline plot | vector |
| pres | Sea level pressure (mb) | value |
| spres | Station pressure (mb) | value |
| ptend | Pressure tendency (mb) | value |
| prec6 | 6 hour precipitation (in) to 2 decimal places | value |
| prec12 | 12 hour precipitation (in) to 2 decimal places | value |
| prec24 | 24 hour precipitation (in) to 2 decimal places | value |
| maxt | 24 hour maximum temperature (F) | value |
| mint | 24 hour minimum temperature (F) | value |
| maxt6 | 6 hour maximum temperature (F) | value |
| mint6 | 6 hour minimum temperature (F) | value |
| conv | Wind convergence (/s) positive is convergence | grid |
| mconv | Moisture convergence (/s) | grid |
| rvort | Relative vorticity (/s) | grid |
| avort | Absolute vorticity (/s) | grid |
| tadv | Temperature advection (K/s) | grid |
| madv | Moisture advection (/s) | grid |
| vadv | Vorticity advection (/s^2) | grid |
The program will now open the graphics window and start processing the data. The user will be prompted for the output device. Then the converted file is opened and data read in. Any additional computations are performed to produce a derived variable and fit the data to a grid. The background map will plot first unless the output is a color fill contour in which the map plots last. The gridding process uses an objective analysis scheme to produce the grids. The parameters for this process are specified in the object_param resource. Once the grids have been created, the maximum and minimum of the grid are displayed for the user to pick an appropriate contour interval. Then, the contour or vector plot will display.
There are several plot types. For contour plots, there is:
- ln - line contours
- dln - dashed line contours
- ndln - negative dashed line contours. All contours less than 0 are dashed. The breakoff can be reset with the con_base resource.
- cf - color fill contours. These are contours where the areas between the contour lines are filled with a progressive color scheme. By default, this is a 15 color scale in which the colors wrap around if there are more than 15 color level. The color scheme can be set by the color_fill resource.
For vectors:
- vect -- vectors/arrows
- strm -- streamlines
- barb -- wind barbs
When the plot is complete, output can be saved to a GIF image file, spooled to the printer or the plot can be zoomed. When zooming the image, the plot will redraw to the new domain. It will also add more stations to the plot depending on the size of the domain. When the user is finished with the plot, the enter key can be hit which closes the window and returns the user to the variable prompt.
Output Files
By default, this program does not produce output files. If a raw or grid file output is desired, use the out_file resource to enable this. By default, this will create a WXP ASCII raw or grid file depending on the plot type. The out_file can be a filename, a file tag (lookup in file name convention file) or a name convention (with wildcards). The output can be GIF file by specifying gif as the file type. It may be desirable to turn plotting of when producing output files. To do this, specify none for the plot_type resource.
EXAMPLES
sfccalc -cu=la -re=mw -va=temp -pl=cf -in=2 -de=d
This produces a color fill contour plot of temperature for the midwest region at an interval of 2.
sfccalc -cu=la -re=mw -va=temp -of=wxp -pl=none
This will generate grid file based on the sfc_grd name convention. A specific filename can be used instead of wxp.
FILES
- sao.cty - the surface station location database file
- sfccalc.var - the variable menu and definitions
SEE ALSO
- sacvt - the surface data decoding program
- smcvt - the synoptic data decoding program.
- sfcwx - the surface data plotting program
- statlog - the surface meteogram plotting program
Last updated July 28, 1998