After a summer of extreme heat, bushfires and dry conditions, forecasters have warned Australians in large parts of the country’s southeast aren’t in the clear yet.
According to Weatherzone, there are signs a very strong, or “super” El Nino could develop in the tropical Pacific Ocean in the coming months.
The prediction follows similar concerns raised by the Bureau of Meteorology that the “super rare” phenomenon – driven by warmer-than-average sea temperatures, and usually lasting between nine and 12 months – may be hurtling toward Australia’s east coast earlier than expected, significantly increasing the risk of further drought and fire.
The official El Nino season has ended, with the El Nino-Southern Oscillation classified as “neutral”, meaning it’s neither La Nina nor El Nino.
“However, there are strong indications that El Nino will emerge as we head into the Southern Hemisphere’s winter,” Weatherzone said.
“The first indicator of the looming El Nino is a large pool of abnormally warm water sitting beneath the surface of the tropical Pacific Ocean … While ocean surface temperatures in the Nino 3.4 region are currently near average for this time of year, there is a large slab of unusually warm water sitting around 50 to 250 metres below the surface.
“These above-average sub-surface temperatures have strengthened in the last couple of months, with anomalies exceeding 6C in some areas.
“It’s possible that these warm sub-surface waters will upwell towards the surface in the coming weeks and months, which could kick off El Nino.”
The second indicator, Weatherzone said, is the “overwhelming agreement” between global forecast models that El Nino is about to emerge – some predicting the phenomenon “will become a very strong event”.
Below average rainfall in winter and spring; above average maximum temperatures for most areas (outside the tropics); “enhanced evaporation” which can, in turn, enhance drought; “more intense daily heat extremes” in southern parts of the country; increased frost risk in winter and spring and increased risk of “dangerous” fire days in the southeast in spring and summer; and a shorter snow season can all be caused by El Nino.
“The strength of El Nino can also affect how it influences Australia’s weather,” Weatherzone said.
“Stronger El Nino events make it more likely that the impacts mentioned above will occur.
“However, it is important to point out that stronger events do not always mean bigger weather impacts and even a weak El Nino can cause significant weather and climate impacts in Australia.”
Sky News Australia meteorologist Rob Sharpe predicted in March “it’s now at least an 80 pet cent chance” of an El Nino event developing.
The Indian Ocean – which “also plays a huge role in governing our rainfall patterns” – is likely to “join forces” with El Nino, he said.
“The two oceans often – but not always – work together. El Ninos often coincide with positive phases of the Indian Ocean. This is likely to take shape this year,” Sharpe predicted.
On the other side of the world, experts are also raising the alarm that the pattern could supercharge extreme weather events and see temperature rises breach 1.5C.
A forecast from Columbia University’s International Research Institute for Climate and Society, published last Monday, suggested El Nino had a 70 per cent chance of developing by June, and a 94 per cent probability of persisting through the end of 2026.
While the UK’s Met Office said in a statement “there is growing confidence that this event could sit at the upper end of the historical range. Scientists are telling us that this could be the strongest El Nino event so far this century”.
“Other organisations around the world have other definitions and thresholds for what constitutes El Nino conditions, but this will be such a significant event, if it happens, that it will be above all of those thresholds and there will be no doubt that we’re in an El Nino,” Met Office climate science communicator Grahame Madge said.
“An El Nino will impart heat into the atmosphere and, generally, raise global average temperatures by around a fifth of a degree Celsius. 1998 was a significant year for global temperature and, at the time, was the warmest year on record, with El Nino contributing to increased temperatures.”
