La Nina over but rain set to continue
The La Nina event that has been impacting eastern Australia has ended, allowing a return to near-average conditions in coming months, Weatherzone says.
La Nina events generally bring above average rainfall to eastern parts of Australia, including Sydney.
The most recent La Nina event occurred predominantly across the spring and summer months and was a contributor to the above average rainfall and floods through many parts of the eastern states.
The key indicators of ENSO (El Niño Southern Oscillation) are now at neutral levels, Weatherzone meteorologist Rob Sharpe said.
This includes the SOI (Southern Oscillation Index), which is a measure of the pressure difference between Tahiti and Darwin, and the Nino 3.4 Index, which is a measure of sea surface temperatures over the central Pacific.
The neutral phase of ENSO will allow rainfall values to tend closer to normal as we move further into autumn and winter.
However, the country is still surrounded by above average sea surface temperatures and the tropical wet season will continue through the end of April, so there is still the risk for above average rainfall and cyclone activity during the next month.
Also, autumn is the wettest season for Sydney, due to an increased frequency of east coast lows over coming months, so the decay of La Nina does not necessarily mean drier times for Sydney.
Weatherzone.com.au is owned by Fairfax Media, publisher of this website.
