Grid Stat Config File Generator


In the first table below are the config file parameters that most users will need to change. Following this are more tables with parameters grouped according to function.

After each table there is a "Submit" button. Clicking any one of them should return a config file to you, unless there is an error. In that case, use your browser's "Back" button to return to this page and fix the problem.


Basic Parameters


Name Input value Explanation
Model A short text string identifying the model being verified. This text string is written out as a header column of the STAT output so that verification statistics from multiple models may be distinguished.
Forecast Field A comma-separated list of model variables and corresponding vertical levels to be verified. The GRIB code itself or the corresponding abbreviation may be used to specify which model fields are to be verified. Each GRIB code must be followed by a level indicator in the form ANNN, ZNNN, PNNN, or PNNN-NNN for an accumulation interval, a single vertical level, a single pressure level, or a range of pressure levels. NNN indicates the accumulation or level value.
Obs Field Can be left blank to use the same field as for the forecast, or it can be specified as in fcst_field.
Forecast Threshold For each forecast threshold listed above one or more thresholds must be specified for use in computing discrete statistics. The thresholds are specified using the Fortran conventions of gt, ge, eq, ne, lt, le to indicate greater than, greater than or equal to, equal to, not equal to, less than, and less than or equal to, respectively. The number of entries in thresholds must match the number of entries in fcst_thresh. However, multiple thresholds may be applied to each GRIB code by provided a space-separated list within single or double quotes.
Obs Threshold Used to define the dichotomous observed yes vs. observed no values for contingency tables. One or more can be specified as for fcst_thresh.
Forecast Wind Threshold A comma-separated list of thresholds to be used when computing VL1L2 partial sums for winds. The thresholds are applied to the wind speed values derived from each U/V pair. Only those U/V pairs which meet the wind speed threshold criteria are retained. To apply multiple wind speed thresholds, separate the threshold values with a space. Use NA to indicate that no wind speed threshold should be applied.
Obs Wind Threshold See above. If the obs_wind_thresh parameter is left blank, it will default to the contents of fcst_wind_thresh.
Mask Grid A comma-separated list of pre-defined NCEP grids over which to perform the grid_stat verification. The predefined grids are specified as GNNN where NNN is the three-digit designation for the grid. Supplying a value of FULL indicates that the verification should be performed over the entire grid on which the data resides.
Mask Polyline A comma-separated list of files that define lat/lon polygons to be used in specifying verification regions.
Output Flag Controls the type of output that the Grid-Stat tool generates. Each flag corresponds to an output line type in the STAT file except for the last one. Setting the flag to 0 indicates that the line type should not be generated. Setting the flag to 1 indicates that the line type should be written to the STAT file only. Setting the flag to 2 indicates that the line type should be written to the STAT file as well as a separate ASCII file where the data are grouped by line type.




Confidence Interval Parameters


Name Input value Explanation
Alpha Values A comma-separated list of alpha values to be used when computing confidence intervals. The confidence interval computed is 1 minus the ci_alpha value.
Bootstrap Interval Specify the method to be used for computing bootstrap confidence intervals. Note that the BCa interval method is computationally intensive.
Bootstrap Proportion Specify a proportion between 0 and 1 to define the replicate sample size to be used when computing percentile intervals. The replicate sample size is set to boot_rep_prop * n, where n is the number of raw data points.
# Resamples Specify the number of times each set of matched pair data should be resampled when computing bootstrap confidence intervals. A value of zero disables the computation of bootstrap confidence intervals.
Random Number Generator Specify the name of the random number generator to be used.
Bootstrap Seed Specify the seed value to be used when computing bootstrap confidence intervals. If left unspecified, the seed will change for each run and the computed bootstrap confidence intervals will not be reproducable.




Smoothing Parameters


Name Input value Explanation
Interpolation Method A comma-separated list of operations to be performed on the forecast field prior to performing verification. The valid values that may be listed are MIN, MAX, MEDIAN, and UW_MEAN for the minimum, maximum, median, and unweighted mean. If multiple interpolation methods are provided, then statistics will be computed separately for each type of smoothing operation.
Interpolation Width A comma-separated list of values to be used in defining the neighborhoods over which the smoothing operation is performed on the forecast field. The neighborhood is simply a square centered on the observation point. The interp_width value specifies the width of that square.
Interpolation Flag The interp flag controls how the smoothing defined above should be applied.
Interpolation Threshold A number between 0 and 1. When performing a smoothing operation over some neighborhood of points the ratio of the number of valid data points to the total number of points in the neighborhood is computed. If that ratio is greater than this threshold, no smoothed value is computed. Setting this threshold to 1, which is the default, requires that the entire neighborhood must contain valid data. This variable will typically come into play only along the boundaries of the verification region chosen.
Neighborhood Width(s) A comma-separated list of values to be used in defining the neighborhood size to be used when computing neighborhood verification statistics. The neighborhood is simply a square centered on the current point and the nbr_width value specifies the width of that square.
Neighborhood Threshold A number between 0 and 1. When performing neighborhood verification over some neighborhood of points the ratio of the number of valid data points to the total number of points in the neighborhood is computed. If that ratio is greater than this threshold, that value is not included in the neighborhood verification. Setting this threshold to 1, which is the default, requires that the entire neighborhood must contain valid data. This variable will typically come into play only along the boundaries of the verification region chosen.
Coverage Threshold A comma separated list of thresholds to be applied to the neighborhood coverage field. The coverage is the proportion of forecast points in the neighborhood that exceed the forecast threshold.




Miscellaneous Parameters


Name Input value Explanation
Rank Correlation Flag Indicates whether or not Kendall's Tau and Spearman's Rank correlation coefficients should be computed. The computation of these rank correlation coefficients is very slow when run over many matched pairs.
Grib Parameter Table Sets the GRIB table 2 parameter version, and thus indicates how to interpret GRIB codes between 128 and 255. The default is 2 and possible values are (2, 128, 129, 130, 131, 133, 140, 141).
Temp Directory Indicates the directory where Grid Stat should write temporary files.
Output Prefix Specifies a string to be used in the output file name. It can be useful for keeping results for different models or variables from overwriting each other.