Image caption
How often (percent) real-time climate model forecasts correctly predict the onset of El Nino (3-month average Nino3.4 values less than or equal to -0.5C) at increasingly far-off lead times. Solid lines represent the multi-model mean of dynamical models. Dotted lines are the multi-model mean of the statistical models. After the first three forecasted seasons, accuracy plummets below 20% in dynamical models. Statistical model accuracy is 0 for most leads except leads 6 and 8. This does not imply that statistical models have more "skill" at these leads as, given the variability in ENSO events and in model forecasts, it is probabilistically likely that models will occasionally correctly predict the onset by chance. Climate.gov image adapted from Ehsan et al., 2024.