Fig. 4: Strategy 2.

a Schematic representation of Strategy 2 (see “Methods”). b One of the dynamical models, ACC, is used when the prediction is made from March during 1982–2018. The thin solid line indicates the ACC of the all-ensemble mean. The dashed-dot line indicates the ACC based on Strategy 2 using “Truth” value as an indicator (sub-ensemble members are 50% of all-ensemble members).