CANBERRA, Sept 18 (Askume) – Australia’s Bureau of Meteorology said conditions in the Pacific Ocean have become La Nina-like in recent weeks, but even if such a weather pattern develops, it is likely to be weak and short-lived.
La Nina and its opposite, El Nino, are caused by cooling and warming of sea surface temperatures over western South America.
Their development is important for global agriculture because La Niña typically brings more rain to Australia, Southeast Asia and India and less rain to agricultural lands in the Americas, while El Niño does the opposite.
U.S. government forecasters this month gave a 71% chance of a La Nina pattern forming between September and November and said it could last until March. Weather forecasters in many other countries also believe La Nina is likely.
The Australian Bureau of Meteorology is more cautious. Its internal climate model suggests that La Nina will not develop.
“Although some atmospheric indicators over the Pacific, such as pressure, cloud cover and trade wind patterns, have been La Niña-like over the past few weeks, it remains to be seen whether these conditions will persist,” the bureau said in a report released Wednesday.
It added, “It is possible that a La Niña event could develop in the coming months, but if it does, it is expected to be relatively weak (in terms of the strength of sea surface temperature anomalies) and short-lived.”
If a La Nina develops this year, it would be the fourth La Nina since 2020, which is extremely unusual as this weather pattern historically forms every three to seven years on average.
Wet weather caused by La Nina led to record-breaking harvests in Australia from 2020 to 2023.
The bureau said forecasts are becoming increasingly uncertain as sea surface temperatures around the world remain at or near record highs.
Climate patterns such as fluctuations between La Nina and El Nino “will not necessarily behave or evolve as they did in the past”, the report says.
