MELBOURNE, Australia — The El Niño–Southern Oscillation (ENSO) remains neutral while the positive Indian Ocean Dipole (IOD) continues to influence the climate of Australia and other parts of the globe, says the Australian Government Bureau of Meteorology in its latest report. A moderate to strong positive Indian Ocean Dipole continues, characterised by cooler waters to the northwest of Australia and warmer waters further west.
While the IOD index has been above threshold for most of the past two months, the general sea surface temperature and cloud patterns have shown positive IOD characteristics since the end of May. It’s likely much of the low rainfall over southern and central Australia during winter has been a result of the positive IOD.
All international climate models surveyed by the Bureau indicate the positive IOD is likely to persist for the southern hemisphere spring. At the beginning of summer, an IOD pattern normally breaks down as the monsoon trough migrates into the southern hemisphere.
Typically, a positive IOD brings below average winter-spring 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. Learn more about the Indian Ocean Dipole.
In the tropical Pacific Ocean, the El Niño–Southern Oscillation (ENSO) remains neutral. Parts of the eastern tropical Pacific are now slightly cooler than average but remain in the neutral range. Most atmospheric indicators are neutral, although the Southern Oscillation Index (SOI) has fallen over the past fortnight due to very high atmospheric pressures at Darwin.
International climate models predict a neutral ENSO state is the most likely scenario for the remainder of 2019, and into early 2020. When ENSO is neutral, it has little influence on Australian and global climate, meaning other influences are more likely to dominate.
