Hotter days ahead as El Niño declared

Climate scientist Professor Steve Turton says many Australians can expect a warm and dry spring and a dry hot summer, thanks to an El Niño declared by the Bureau of Meteorology (BoM) this week.

“For eastern and southern Australia, we can expect a warm and dry spring and a dry hot summer, with increased risks for an early and severe bushfire season (already happening), much below-average rainfall, greater risk for above-average maximum temperatures, and severe heatwaves, dust storms and agricultural and ecological droughts,” Professor Turton explained.

“Southwestern parts of the continent are less exposed to El Niño events,” he said.

Professor Turton said that during spring and early summer, a positive Indian Ocean Dipole was expected to enhance the warming and drying effects of the El Niño. 

“The last time we had both climate drivers co-occurring was in 1982/1983 - still the driest year on record for all of Australia,” he warned. 

“The 1983 catastrophic ‘Ash Wednesday’ fires and Melbourne dust storm are still natural disaster standouts in Australian modern history.”

Professor Turton said after the triple La Niña, there had been considerable re-growth across forest and grassland areas, bringing a much higher risk for severe or catastrophic (Code Red) bushfire events.

Professor Turton said those living in Northern Queensland could expect a delayed wet season due to the El Niño influence.

“There is a lower risk for widespread monsoonal flooding, compared with La Niña or neutral years and less tropical cyclone activity in Australian longitudes as the warmer ocean waters shift toward the central tropical Pacific,” he explained.

“The Great Barrier Reef is highly exposed to severe and widespread coral bleaching events during an El Niño due to the weakening (and sometimes reversal) of the trade winds. 

“A lack of wind and ocean swells, together with low cloud and high solar radiation levels warms up the water column across shallow coral reefs. When the number of accumulated heat days reaches a critical threshold coral bleaching occurs.”

Professor Turton said during the 2015/16 El Niño, a severe and widespread coral bleaching event affected most of the reef north of Cairns and about 50 per cent of the corals died in that event.