Metrics Reference¶

Continuous Cell-Level Metrics¶

These metrics are computed at every grid cell for every timestep.

Key	Name	Formula	Units
`ne`	Normalised Error	`(test - source) / source * 100`	percent
`ane`	Absolute Normalised Error	`abs((test - source) / source) * 100`	percent
`rse`	Root Squared Error	`sqrt((test - source)^2)`	same as variable
`bias`	Mean Error (Bias)	`test - source`	same as variable
`mae`	Mean Absolute Error	`abs(test - source)`	same as variable

Require a threshold parameter. Events are defined as values exceeding the threshold.

Key	Name	Formula	Range
`pod`	Probability of Detection	`Hits / (Hits + Misses)`	0--1
`far`	False Alarm Ratio	`False Alarms / (Hits + False Alarms)`	0--1
`csi`	Critical Success Index	`Hits / (Hits + False Alarms + Misses)`	0--1
`fbias`	Frequency Bias	`(Hits + False Alarms) / (Hits + Misses)`	0--inf

Computed over the spatial domain for each timestep.

Key	Name	Description
`ne`	Normalised Error	NE computed from domain-summed values
`ane`	Absolute Normalised Error	ANE computed from domain-summed values
`rmse`	Root Mean Square Error	Spatially aggregated RMSE
`bias`	Mean Error	Spatially aggregated bias
`pearson`	Pearson Correlation	Spatial correlation coefficient (-1 to 1)
`pod`	Probability of Detection	From domain contingency table
`far`	False Alarm Ratio	From domain contingency table
`csi`	Critical Success Index	From domain contingency table
`gss`	Gilbert Skill Score	Equitable threat score from domain contingency table
`fbias`	Frequency Bias	From domain contingency table

Per-station time series metrics.

Key	Name	Description
`bias`	Mean Bias	Mean difference (model - obs)
`mae`	Mean Absolute Error	Mean absolute difference
`rmse`	Root Mean Square Error	RMS of differences
`ne`	Normalised Error	Normalised by observed values
`ane`	Absolute Normalised Error	Absolute normalised difference
`pearson`	Pearson Correlation	Temporal correlation per station

Vector wind evaluation from U/V components.

Key	Name	Units	Description
`vector_rmse`	Vector RMSE	m/s	`sqrt(mean(du^2 + dv^2))`
`speed_bias`	Wind Speed Bias	m/s	`mean(test_speed - source_speed)`
`direction_bias`	Wind Direction Bias	degrees	Mean directional difference (-180 to 180)

Spatial verification at multiple neighborhood scales (default: 1, 3, 5, 9, 17, 33, 65 grid cells).

Requires a threshold parameter to binarize the fields before computing fractions.

Any of the following metrics grouped by hour-of-day (0--23):

bias, rmse, mae, pearson

Supports a utc_offset parameter for local time conversion.