12-Month Rainfall Forecast

Issue Notes

ENSO status: Neutral IOD status: Neutral SAM status: Trending neutral Sea surface temperatures (SSTs) across the equatorial central Pacific remained stable throughout February with the Nino3.4 index registering a value of 0.3. On the other hand, the Southern Oscillation Index (SOI) recorded a value of -2.2 in February. The current outlook suggests slightly warmer than average SSTs will persist across the equatorial Pacific Ocean through the austral autumn, potentially cooling further by the austral winter. Four out of seven international models maintain a slightly warmer than average equatorial Pacific Ocean through the first half of winter. To the west of Australia, the Indian Ocean Dipole (IOD) remains neutral, normal for this time of the year. All six international models maintain neutral IOD values through to the austral winter. In terms of precipitation across Australia, the current outlook favours below average rainfall for western, central and southeastern parts of the country. Across NSW and Qld, the outlook is for average-to-above average, mainly across the Qld coasts. This excludes any extreme weather events such as tropical cyclones or East Coast Lows. Across the north, the North Australian Monsoon (NAM) has been quiet for most of the wet season, with the current prognosis suggesting below average rainfall for March but above average in April. Looking further ahead, with no significant signature from ENSO, there are no significant climate drivers tilting the balance towards a drier or wetter end of autumn/winter. The current consensus, however, suggests that average to above average rainfall is a possibility across northern, western and parts of the inland south east.