During April 2019, the atmosphere once again responded to a warm pool of water in the central and western Pacific, withabove normal rainfall and cloud centred along and just west of the International Dateline.
Rainfall and sea surface temperature (SST) patterns remained consistent with a weak, central Pacific El Niño.While the flavour of El Niño has been closer to the central-based type over the last few months, the eastward propagation of anomalously warm ocean water may signal that the event is transitioning to an east-based one. This transition could bring more traditional El Niño impacts for the Pacific Islands, such as increased rainfall for northern and eastern island groups and reduced rainfall for western and southwestern island groups.
According to the consensus from international models, the probabilityfor oceanic El Niño conditions is 83% for the May-July period. Beyond this, for the August to October period, the probability for oceanic El Niño conditions is 64%. For November 2019 to January 2020, El Niño remains the most likely outcome at 58%. This continues to suggest the potential for a ‘protracted’ event (multi-year duration).