Prediction performance of space weather forecast centers following the extreme events of October and November 2003

A review and analysis of the five strongest interplanetary coronal mass ejection (ICME) events of late October and early November 2003 (the strongest events of the “Halloween” epoch) are studied with respect to the prediction performance of five space weather forecast centers. Accurate time‐of‐arrival predictions and rapid responses to the upstream detection of strong ICMEs are of paramount importance to critical infrastructures such as power companies. Prediction and performance analysis results indicate that (1) the average time‐of‐arrival error for all forecast centers was 9.26 hours, which is consistent with the guidance errors associated with the leading shock propagation prediction models; (2) time‐of‐arrival predictions from Solar Terrestrial Dispatch (STD) surpassed all others in accuracy, with an average time‐of‐arrival prediction error of 1.22 hours; (3) overall, the strongest ICME impact events of 29 and 30 October were the most poorly predicted; (4) the most accurate shock propagation prediction model operated by the Geophysical Institute of the University of Alaska Fairbanks was the HAFv.2 model; and (5) STD provided the most rapid notification to the Northeast Power Coordinating Council concerning the detection and imminent arrival of most of the ICMEs. A better method of conveying time‐of‐arrival prediction information is presented that may be more easily digested by consumers of space weather services.