NOAA / Space Weather Prediction Center

K5 Warning Lead Time Plot


This 2x2 contingency table summarizes the joint distribution of SWPC next-day G1 or greater storm forecasts from 7/25/2012 to 12/31/2013. The "Correct Null" value in the table represents the number of days in the period for which no warning was issued and no G1 or greater activity occurred. The summary statistics derived from the contingency table include the frequency Bias (values greater than 1 indicate more warnings were issued than events observed), Critical Success Index (also called the Threat Score), Probability of Detection (POD), and the False Alarm Ratio (FAR). The POD is currently the SWPC GPRA metric. Detailed definitions of these metrics are in the Verification Glossary.

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