The Bureau of Meteorology (BoM) has confirmed an El Niño weather event is officially underway.
This means weather will be hotter and drier in coming months.
It comes after three consecutive La Niña summers in Australia.
What is El Niño?
El Niño is a weather event characterised by unusually warm waters in the central and eastern Pacific Ocean. In Australia, it causes higher temperatures and can lead to droughts.
Unlike increased rain caused by La Niña, the most direct consequence of El Niño is less rainfall.
It also causes more individual days of extreme heat, such as this week’s unseasonably high temperatures in the east coast.
Positive IOD
The BoM also confirmed a “positive IOD event” is underway.
IOD stands for Indian Ocean Dipole. It refers to the difference in sea surface temperatures between two areas, or poles.
A ‘positive’ event means warmer sea temperatures in the western Indian Ocean, less cloud cover in Australia’s northwest, and less rainfall in the country’s south and far north.
When a positive IOD event and El Niño happen at the same time, a BoM spokesperson said the combination increases the “severity of rainfall deficiencies… for the southeast of the continent.”
Fire danger
The NSW Rural Fire Service issued the first total fire ban for Greater Sydney since November 2020 today.
The fire danger for NSW’s South Coast, where 20 schools were closed today, was later upgraded to ‘catastrophic’.
