Extratropical forcing of ENSO

We present evidence that sea surface temperatures in the North Pacific, South Atlantic, and South Indian Oceans during late boreal winter offer another important source of predictability for El Niño Southern Oscillation (ENSO). This new SST predictor may provide accurate prediction of the amplitude of ENSO events before their onset, for both El Niño and La Niña events which occurred during recent decades. Key Points definition of a new extratropical SST precursor for ENSO predictability the new precursor offers an independent source of forcing for ENSO accurate prediction of the amplitude of ENSO events during recent decades.