Run

Run cindyhg Thu, 04/25/2019 - 10:21

Next, run Point-Stat on the command line using the following command:

point_stat \
$MET_TUTORIAL_DATA/input/sample_fcst/2007033000/nam.t00z.awip1236.tm00.20070330.grb \
$MET_TUTORIAL_DATA/output/pb2nc/tutorial_pb.nc \
$MET_TUTORIAL_DATA/config/PointStatConfig_tutorial \
-outdir $MET_TUTORIAL_DATA/output/point_stat \
-v 2

Point-Stat is now performing the verification tasks we requested in the configuration file. It should take a minute or two to run.

In this example, Point-Stat accumulates matched forecast/observation pairs into 48 groups based on our configuration file selections. The 48 groups are a result of: 4 fields (TMP at Z2, TMP at P750-850, UGRD at Z10, VGRD at Z10) * 2 observing message types * 3 masking regions * 2 interpolation methods. However, many of these combinations, such as verifying TMP at Z2 versus upper-air observations (ADPUPA), will result in zero matched pairs being found. As Point-Stat runs, you should see several status messages printed to the screen to indicate progress.

The configuration file language allows you greater control of which message types are used for each verification task. Instead of trying all 48 combinations listed above, you could specify which message type(s) should be used for verifying each field. Simply move the message_type setting inside each entry of the field array. Use ADPSFC to verify the surface fields (TMP at Z2, UGRD at Z10, and VGRD at Z10), and use ADPUPA to verify the upper-air field (TMP from 750 to 850mb).

While Point-Stat has the ability to compute bootstrap confidence intervals, doing so is rather slow. For this reason, bootstrapping is disabled by default. To turn them on, edit the configuration file $MET_TUTORIAL_DATA/config/PointStatConfig_tutorial, in the boot dictionary, set n_rep equal to 1000, and re-run the previous Point-Stat command.

While Point-Stat has the ability to compute rank correlation statistics, doing so is rather slow. For this reason, rank correlations are disabled by default. To turn them on, edit the configuration file $MET_TUTORIAL_DATA/config/PointStatConfig_tutorial, set the rank_corr_flag variable equal to TRUE, and re-run the previous Point-Stat command.

Next, we'll take a look at the Point-Stat output we just generated.