radmask

Sections

NAME
SYNOPSIS
PARAMETERS
DESCRIPTION
EXAMPLES
FILES
SEE ALSO

NAME

radmask - Radar mosaic winter mask and clutter filter setup program

SYNOPSIS

radmask [parameters...] filename

PARAMETERS

Command Line	Resource	Default	Description
-h	help	No	Lists basic help information.
-df=filename	default	wxp.cfg	Sets the name of the resource file.
-na=name	name	radmask	Specifies the name used in resource file parsing.
-me=level	message	out2	Specifies level of messages to be displayed out3 - list sites and params going into list file
-fp=path	file_path	the current directory	Specifies location of database files.
-dp=path	data_path	the current directory	Specifies the location of the input raw data files.
-gp=path	grid_path	the current directory	Specifies location of gridded output files from WXP.
-mp=path	model_path	the current directory	Specifies location of raw model GRIB data
-nc=name_conv	name_conv	name.cnv or name_conv file	This sets which name convention file to use.
-if=in_file	in_file	program specific	Specifies the input file name tag.
-of=out_file	out_file	bref_list	Specifies the name convention of the output radar list file.
-mo=model	model	None	Sets the input forecast model
-cf=filename	city_file	ruc	Specifies the radar location database.
-cu=[hour]	current	none	This specifies to use current data files.
-ho=hour	hour	none	Specifies the exact hour that a data file is valid for.
-nh=hours[,skip]	num_hour	Value Generally 0	Specifies the number of hours worth of data to use in the program
-ft=time	time	init	This is used to offset the model data to a more appropriate time.
-pd=domain	plot_domain	ps,38.5,-98,700,500,.08,.08	Sets the plotting domain
-nf name conv	nids_file	bref_list	Specifies the name convention for the NIDS files used in nids2image. This goes into the output radar list file.
-pm grid conv	prec_mask	winmask	Specifies the name convention used to save the output winter precipitation mask.
-pa=param[,param...]	parameter	none	Specifies addition parameters to program.
filename (positional)	filename	none	Specify input filename

DESCRIPTION

The radar mask program performs two functions:

winter mask - This is a grid file defining where liquid, mixed and frozen precipitation are falling
radar list file - This is a text file with a list of sites to be included into the radar mosaic.

Winter precipitation mask

The program creates a winter precipitation mask from model data. The output is a grid of values: 0 for rain, 1 for mixed and 2 for frozen/snow. The grid used is specified with the resrc:plot_domain resource. This does not have to match the radar mosaic output since prog:nids2image will interpolate but it should be roughly the same resolution or better than the input model grids.

The input are model grids, preferably from the RUC/RAP model. The model is specified with the resrc:model resource. There are six grids used in the two algorithms:

1hr:2m_ag:temp - 2m AG temperature (C)
1hr:2m_ag:rhum - 2m AG relative humidity
1hr:0-30mb_ag:temp - 0-30mb AG temperature (C)
1hr:60-90mb_ag:temp - 60-90mb AG temperature (C)
1hr:150-180mb_ag:temp - 150-180mb AG temperature (C)
1hr:150-180mb_ag:rhum - 150-180mb AG relative humidity

The temperatures are used to determine precip type (liquid, mix, frozen) and to determine inversions for AP (Anomalous Propagation). The relative humidities are used to estimate moisture and cloud cover. Clutter and AP are less likely in dry conditions. Also, in cold conditions, the clutter mask should be less because clutter is less of an issue and snow is tougher to pick up on radar.

The resrc:time resource is used to specify a forecast offset. For example, the model might be nearly an hour old when it's processed. So it's more appropriate to use the 1 hour forecast (the default).

The program will compute a winter weather radar mask grid. This default grid is a 8km grid over the CONUS region. This can be changed with the resrc:plot_domain resource. The grid will be saved to the file specified by the resrc:prec_mask resource.

Radar list file

The program will create a radar list file. This contains a list of radar sites given by a name convention. Each line contains a single site and is formatted as:

name [flag] [param]

The default name convention is specified with the resrc:nids_file resource. The site ID is tack onto the end of the convention tag. For example, if nids_file is "nids_n0r", the output will be "nids_n0r:i=id" where ID is the 3 letter site identifier of the radar. The program will also use the RUC model data to produce a site specific clutter removal ramp function. An example of a radar list is:

nids:t=n0r:i=ABR ramp:35:350
nids:t=n0r:i=ABX ramp:35:350
nids:t=n0r:i=AKQ ramp:35:350
nids:t=n0r:i=AMA ramp:30:300
nids:t=n0r:i=AMX ramp:35:350
nids:t=n0r:i=APX ramp:40:400
nids:t=n0r:i=ARX ramp:35:350

The program uses the "rad.cty" database to create the radar list. It uses any radar site with a priority or 1 or 2 and omits non-US sites. The radar station database can be changed with the resrc:city_file resource.

Program execution

This program should be run once an hour after the arrival of the latest RUC/RAP model run. The file list and winter mask will be used by the prog:nids2image radar mosaic program.

EXAMPLES

```
radmask -ft=1 -mo=ruc4 -nids_file=nids:t=n0q
```
This will use the RUC 40 km model grids as input, n0q hi-res NIDS files in the mosaic, and uses the winmask_path resource to point to the output directory.

FILES

rad.cty - the radar station location database file