Fig. 2: Strategy 1, dynamical-DL based on ensemble mean forecast.

a The ACC of 3D-Geoformer (red), CNN (pink), dynamical-model mean (black), and strategy 1 (blue) for year-round. b Same as (a), except for the initial month in March. c The seasonality of the prediction skill with shading of ACC of Strategy 1 during 1982–2018. The shading around the lines denotes the 95% confidence interval, based on the bootstrap method. Note that the intervals of DL models are relatively small, making them less visually apparent in the figures.