MELBOURNE, Australia – In the tropical Pacific Ocean, the El Niño–Southern Oscillation (ENSO) remains neutral, while in the Indian Ocean the strong positive Indian Ocean Dipole (IOD) event continues, reports the Australian Government Bureau of Meteorology. IOD values remain strongly positive but have weakened slightly over the past fortnight.
Waters are warmer than average near the Horn of Africa, and cooler than average waters persist in the eastern Indian Ocean, south of Indonesia. International climate models surveyed by the Bureau indicate the positive IOD is likely to be slower to decline than usual, and may persist into mid-summer.
Typically, a positive IOD brings below average rainfall to southern and central Australia with warmer days for the southern two-thirds of the country. Positive IOD events are often associated with a more severe fire season for southeast Australia.
In the tropical Pacific Ocean, the El Niño–Southern Oscillation (ENSO) remains neutral. While tropical Pacific Ocean sea surface temperatures are slightly warmer than average, atmospheric indicators are generally neutral.
Trade winds have recently weakened temporarily in the western Pacific region in line with severe tropical cyclone Rita.
This may mean there is some warming of surface waters in the coming few weeks.
However, most climate models forecast ENSO-neutral conditions for the rest of 2019 and into the first quarter of 2020. When ENSO is neutral, it has little effect on Australian and global climate, meaning other influences are more likely to dominate.