mosplot

Sections

• NAME
• SYNOPSIS
• PARAMETERS
• DESCRIPTION
• EXAMPLES
• FILES
• SEE ALSO

NAME

mosplot - MOS data plotting

SYNOPSIS

mosplot [parameters...] filename

PARAMETERS

DESCRIPTION

This program plots and contours MOS (Model Output Statistics) data on a background map. The input to the program is a raw ingested MOS data file. This is different from other WXP plotting programs in that MOS data is regularly formatted so a decode/conversion process is not necessary. Then, based on a plot domain, forecast time and a variable selected by the user, a plot is generated. Overlay plots, contour plots and loops can also be generated if the appropriate options are set.

The program will display data from 4 different model sources:

1. NGM - MOS statistical forecast data derived from the NGM model.   This includes many parameters such as max/min temperature, 3 hourly estimates of temperature, dewpoint, precipitation, winds, etc.
2. NGM_UA - This is derived directly from the NGM model grids and represent data such as boundary layer temperature, relative humidity, sea level pressure, lifted index, 1000-500 mb thickness and vertical velocity.
3. ETA_UA - This is very similar to the NGM_UA except the data are from the ETA model.  This includes lowest level temperatures, relative humidity, sea level pressure, lifted index, 1000-500 mb thickness and vertical velocity.
4. MRFX - This is derived extended range forecast data taken from the MRF model run once a day. The data include max/min temperature, probability of precipitation, winds, and cloud coverage reported once every 12 hours.

The model type can be changed with the model resource.

The plot domain defaults to the contiguous US unless changed through the plot_domain resource. The domain can be interactively changed using the mouse once the plot has been generated.

The programs starts off by prompting the user for input MOS file name.  For some ingestors, such as the LDM, the list may contain many files that don't contain plottable MOS data.  Only the 0 and 12Z data files are usable. 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 mos_dat tag but this can be changed with the in_file resource.

NOTE: The program assumes that the model data for all model types are contained in a single file type represented by the mos_dat tag. If the model types are in different files, the tag must be specified in the in_file resource. Both model and tag can be specified simultaneously if the model type is contained in the tag.  For example, using mos_ngm_ua for the tag for NGM_UA data.  The program will see the "ngm_ua" in the tag and use that model type.

Next, the program prompts the user for the forecast time. This is done through a forecast time menu which is specified in the focalc.tim file. Remember, each model type has a specific set of valid forecast times.

After the forecast time has been set, the city database is read in and a cross-reference table is setup. Since MOS data does not have 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 focalc.var file. The internal variables are

These parameters can be accessed by name if they have not been redefined in the focalc.var file. Otherwise, prepending a "+" to the variable name will guarantee these variables will appear.

There are several derived variables from this list which are defined in the focalc.var file. These include composite plots, overlay plots and computed grids.

The program will now open the graphics window and start processing the data. The user will be prompted for the output device. Then the data 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.

Present Weather Determination

The estimated type of weather on NGM plots is based on the following information:

1. Precipitation based on probability of precipitation > 30%,
2. Precipitation type based on PTYPE field (rain, snow, freezing rain),
3. Precipitation intensity based on quantitative precipitation QPF field (see below),
4. Existence of thunderstorms based on probability of thunderstorm > 20%,
5. Existence of severe thunderstorms based on severe thunderstorm probability > 30%,
6. Existence of obscuration (fog/haze) based on VIS field < 1 mile where obscuration type determined by OBVIS field.

Precipitation type and intensity based on 6 hour information

Precipitation type and intensity based on 12 hour information

EXAMPLES

   focalc -cu=la -ft=h24 -va=extt -de=d -pl=cf -in=2

This contours the extreme temperature for the US in color fills with an interval of 2.

   focalc -cu=la -ft=h24 -va=temp -of=wxp -pl=none

This will generate grid file based on the mos_grd name convention.  A specific filename can be used instead of wxp.

   focalc -mo=mrfx -cu=la -ft=d4 -va=maxt

This contours maximum temperatures from the MRF MOS.

FILES

• mos.cty - the surface station location database file
• focalc.tim - the time menu
• focalc.var - the variable menu and definitions

SEE ALSO

Last updated November 2013