ESPERTA probability contours for the prediction of ≥S1 SPEs for three solar longitude bands (Laurenza et al. 2007; Alberti et al. 2017). Symbols: open circles outside contours—correct null forecasts; open circles inside contours—false alarms; stars—≥S1 SPEs not predicted (Misses); diamonds—correctly predicted ≥S1 SPEs (Hits); ≥S1 SPEs not preceded by ≥M2 flares—MISSES (not plotted). Color coding gives the NOAA Radiation Storms scale (Table 1).