Output

Output cindyhg Wed, 04/24/2019 - 12:31

When Gen-Vx-Mask is finished, you may view the output NetCDF file it wrote using the ncdump and ncview utilities (if available on your machine). Run the following commands to view the contents of the NetCDF files:

ncview $MET_TUTORIAL_DATA/output/gen_vx_mask/CONUS_G212_poly.nc &
ncdump -h $MET_TUTORIAL_DATA/output/gen_vx_mask/CONUS_G212_poly.nc
ncview $MET_TUTORIAL_DATA/output/gen_vx_mask/circle_mask.nc &
ncdump -h $MET_TUTORIAL_DATA/output/gen_vx_mask/circle_mask.nc

The output of ncdump indicates that the NetCDF file contains a variable named CONUS, which is the name defined for this polyline in the input Lat/Lon file. The ncview window should display a plot similar to Figure 2 below. We'll use this NetCDF output file from Gen-Vx-Mask to define verification masking regions for the other MET tools.

Figure 2: Output of the Gen-Vx-Mask tool showing CONUS region defined over NCEP Grid 212.
Figure 2: Output of the Gen-Vx-Mask tool showing CONUS region defined over NCEP Grid 212.

The output of ncdump indicates that the NetCDF file contains a variable named MLB_Stadiums, which is the name defined for this masking region in the input Lat/Lon file. The ncview window should display a plot similar to Figure 3 below.

Figure 3: Output of the Gen-Vx-Mask tool showing the Major League Baseball Stadium masking regions defined over NCEP Grid 212.
Figure 3: Output of the Gen-Vx-Mask tool showing the Major League Baseball Stadium masking regions defined over NCEP Grid 212.

Additional Examples

The following examples illustrate the definition of more complex masks. After running each example, use ncview to display the results.

  • Change the threshold for circle masking:
gen_vx_mask \
-type circle -thresh '>=400' \
$MET_TUTORIAL_DATA/input/sample_fcst/2005080700/wrfprs_ruc13_24.tm00_G212 \
$MET_BASE/poly/MLB_Stadiums.txt \
$MET_TUTORIAL_DATA/output/gen_vx_mask/circle_ge400_mask.nc

  • Apply data masking where surface pressure is below 850mb and intersect with the CONUS mask:

gen_vx_mask \
-type data -intersection \
$MET_TUTORIAL_DATA/output/gen_vx_mask/CONUS_G212_poly.nc \
-input_field 'name="CONUS"; level="(*,*)";' \
$MET_TUTORIAL_DATA/input/sample_fcst/2005080700/wrfprs_ruc13_12.tm00_G212 \
-mask_field 'name="PRES"; level="Z0";' -thresh 'le85000' \
$MET_TUTORIAL_DATA/output/gen_vx_mask/sfcpres_850_and_conus_mask.nc 
  • Apply box masking and complement :
gen_vx_mask \
-type box -height 5 -width 10 -complement \
$MET_TUTORIAL_DATA/input/sample_fcst/2005080700/wrfprs_ruc13_24.tm00_G212 \
$MET_BASE/poly/MLB_Stadiums.txt \
$MET_TUTORIAL_DATA/output/gen_vx_mask/box_complement_mask.nc
  • Compute track distances with no threshold:
gen_vx_mask \
-type track \
$MET_TUTORIAL_DATA/input/sample_fcst/2005080700/wrfprs_ruc13_24.tm00_G212 \
$MET_BASE/poly/MLB_Stadiums.txt \
$MET_TUTORIAL_DATA/output/gen_vx_mask/track_distance.nc