Early Action Rainfall (EAR) Watch
Current El Niño-Southern Oscillation (ENSO) status: The Australian Bureau of Meteorology's ENSO Outlook remains at La Niña ALERT. This means the chance of La Niña forming in 2020 is around 70%—roughly three times the average likelihood. La Niña could become established in the next three months. La Niña is normally associated with wetter than normal conditions in the southern Cook Islands and drier than normal conditions in the northern Cook Islands (opposite during El Niño).
Status summary: Meteorological drought existed at Penrhyn 12 months ago. Rainfall has returned to normal in the last few months.
Outlook summary: For September, a medium chance dry alert is in place for Penrhyn and low chance dry alerts for Rakahanga and Manihiki. For the Southern Group, there is low chance wet alerts for Aitutaki, Rarotonga and Mangaia and medium change dry alerts for the eastern islands.
For September to November, high chance dry alerts are in place for Penrhyn, Rakahanga and Manihiki and a low chance dry alert for Pukapuka. For the Southern Group, there are low chance wet alerts for Palmerston, Aitutaki and Manuae and low chance dry alerts for Atiu and Rarotonga. See table/maps below for additional information. It is very likely the northernmost Cook Islands will transition into meteorological drought in the coming months. See status table below for potential impacts.