The Australian Bureau of Meteorology says the tropical Pacific Ocean is in the early stages of a late forming La Niña event, which they expect to strengthen into the end of the year. However, they say current observations indicate this La Niña will be considerably weaker than the strong 2010-11 event.
"La Niña periods are usually, but not always, associated with above-normal rainfall during the second half of the year across large parts of Australia, most notably eastern and northern regions," says the bureau. "Daytime temperatures are typically cooler-than-average and tropical cyclone risk for northern Australia increases during the cyclone season (November-April). Rainfall is also affected by local factors such as the temperature of the oceans surrounding Australia’s northern coasts. These temperatures are currently cooler than they were at the same time in 2010, suggesting a weaker influence on Australian rainfall."