MELBOURNE, Australia – The El Niño–Southern Oscillation (ENSO) remains neutral: the positive Indian Ocean Dipole (IOD) continues to be the main influence on Australian climate, reports the Bureau of Meteorology (BOM) of the Australian Government in its latest wrap-up. The IOD index has generally been above the positive IOD threshold since mid-July.
The broader Indian Ocean patterns of sea surface temperature, cloud, and wind have been positive IOD-like since late May, contributing to dry conditions affecting most of Australia.
All climate models surveyed by the Bureau indicate the positive IOD is likely to continue for the southern hemisphere spring. Typically, a positive IOD brings below average winter–spring rainfall to southern and central Australia, above average daytime temperatures for the southern two-thirds of Australia, and an increased fire risk in the southeast.
The tropical Pacific Ocean remains neutral with respect to the El Niño–Southern Oscillation (ENSO). Atmospheric and oceanic indicators of ENSO are generally close to average, reflecting neutral tropical Pacific cloud and rainfall patterns.
Most climate models indicate the tropical Pacific is likely to remain ENSO-neutral for the rest of 2019 and into early 2020, meaning other climate drivers, like the IOD, are likely to remain as the primary influences on Australian and global weather.