Professor Mark Howden,from the Australian National University’s Institute for Climate,Energy and Disaster Solutions,said temperatures were edging up towards uncharted territory in the eastern Pacific Ocean.
The El Nino weather pattern occurs when sea temperatures in the central and eastern Pacific Ocean heat up. This disrupts typical ocean currents and trade winds and brings colder water to the east coast of Australia,meaning less evaporation and rain and a significant rise in the risk of drought,heatwaves and bushfires.
The flipside is a La Nina cycle,which tends to bring wet conditions like the record rain and floods seen across NSW,Victoria and Queensland over the past three years.
While the Bureau of Meteorology has taken a relatively cautious approach –issuing an “alert” for likely El Nino conditions without formally declaring the start of a cycle – Howden said it was “very,very clear that we’ve got an El Nino”.
“Most of the other big institutes like NOAA[National Oceanic and Atmospheric Administration] in the US – their conclusion[earlier this month] was more than a 90 per cent chance of an El Nino. And things have firmed up since then.”
Howden said “extraordinary” temperatures were being recorded in the surface waters of the eastern Pacific along the South American coastline,which,coupled with a large mass of warm water below,indicated the likely formation of an El Nino event.