The term La Niña has occupied the thoughts of many Australians over the past couple of years. The weather event has meant that our usually toasty summer months have been filled with cooler weather and rainfall, and frankly, it’s been a bit of a drag.
We know that the weather event is officially back for a third year in a row (damn her), but how long is the wet predicted to stick around? Here’s what we know about Australia’s weather movements for the rest of the year.
What is a La Niña weather event?
According to the Bureau of Meteorology (BOM): “La Niña is part of a cycle known as the El Niño-Southern Oscillation (ENSO), a naturally occurring shift in ocean temperatures and weather patterns along the equator in the Pacific Ocean.”
“During La Niña, waters in the central or eastern tropical Pacific become cooler than normal, persistent south-east to north-westerly winds strengthen in the tropical and equatorial Pacific, and clouds shift to the west, closer to Australia.”
What does this mean for weather in Australia?
The BOM states that La Niña typically results in above-average rainfall for Australia – particularly across eastern, central and northern regions.
It will also likely mean cooler days, more tropical cyclones, and an early onset of the first rains of the wet season across the north.
BOM’s head of climate operations, Dr Andrew Watkins, said of the announcement that:
“La Niña also increases the chance of cooler than average daytime temperatures for large parts of Australia and can increase the number of tropical cyclones that form.
“La Niña is also associated with earlier first rains of the northern wet season, as we’ve observed across much of tropical Australia this year.”
Prior to 2020, the last time Australia experienced a La Niña event was between 2010 and 2012, resulting in one of our wettest two-year periods on record.
Sadly, this also meant Australians experienced widespread flooding in many parts of the country due to record rainfall. Five of the tropical cyclones that occurred in Australia between 2010 and 2011 were in the severe category, including Tropical Cyclone Yasi, which caused much devastation to far north Queensland.
The last La Niña event before 2022 occurred in 2020/21, but Watkins stressed that it is not unusual for back-to-back events to occur like this.
What’s the latest from the Bureau of Meteorology?
The BOM confirmed in September that its ENSO Outlook status had moved to ‘La Niña’ (up from its previous ALERT status). In short, the weather event has been declared for another year. This is the third time we’re seeing this weather status in a row. And according to the ABC, these kinds of events are relatively rare.
The BOM wrote of this event:
Models indicate this La Niña event may peak during the spring and return to neutral conditions early in 2023. La Niña events increase the chances of above-average rainfall for northern and eastern Australia during spring and summer.
When will La Niña end for us?
This time around, it’s estimated by the BOM that Australia will return to ENSO-neutral condition (which means no La Niña or El Niño events) in early 2023. There is a light (the sun) at the end of the tunnel, folks. Here’s hoping we can sit in that light for a while this time around.
This article was originally published on 30/9/20 and updated to reflect the news of the latest event.