Issue Notes

ENSO status: Neutral
Indian Ocean Dipole (IOD): Neutral

Sea surface temperatures (SSTs) and atmospheric indicators across the equatorial Pacific Ocean remain within neutral values.

The Nino3.4 index dropped to 0 in May for the first time since August 2017. On the other hand, the Southern Oscillation Index (SOI) recorded a value of 2.1 in May.

Current consensus suggest neutral ENSO conditions through the southern hemisphere winter. Long range forecasts continue to hint at the possibility of an El Nino event towards the end of 2018, though only three out of eight international models reach El Nino thresholds by the end of the year.

Warmer than average sea surface temperatures (SST) remain across the eastern seaboard as well off South Australia and Tasmania. These, however, have experienced some cooling since the end of summer.

Climate forecasts favour average-to-below average rainfall for most of Australia's southern half in June, with below average rainfall likely to persist across the eastern states through to August. Warm SSTs off the eastern seaboard could bring some relief rainfall east of the ranges across NSW and eastern Victoria, most likely through intense weather events.

Due to the lack of rainfall through the first half of 2018 most of NSW, far north western Victoria and southeastern SA, 5-month rainfall deficiencies remain at serious-to-severe deficiency levels.

In the longer term, there risk for a possible El Nino-like conditions during the second half of 2018, could favour a drier than average outlook for the eastern half of the country through spring.