Abstract
The El Niño-Southern Oscillation (ENSO) phenomenon – the dominant
source of climate variability on seasonal to multi-year timescales – is
predictable a few seasons in advance. Forecast skill at longer
multi-year timescales has been found in a few models and forecast
systems, but the robustness of this predictability across models has not
been firmly established owing to the cost of running dynamical model
predictions at longer lead times. In this study, we use a massive
collection of multi-model hindcasts performed using model analogs to
show that multi-year ENSO predictability is robust across models and
arises predominantly due to skillful prediction of multi-year La Niña
events following strong El Niño events.