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.
Now, in encouraging news, the Bureau of Meteorology (BOM) has announced that as of June 21, 2022, “The 2021–22 La Niña event has reached an end”. However, it also warned that the annoying gal might be back later in the year.
Here’s what we know about La Niña’s movements for the rest of the year.
What is a La Niña weather event?
According to the 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 La Niña 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, according to the BOM.
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.
How likely is it to return?
The BOM has confirmed that its ENSO Outlook status has moved to La Niña WATCH presently. This category means there is a 50 per cent chance of La Niña returning in late 2022 – which is double the usual likelihood.
Guess we will have to watch this space and see what’s to come. (Cross your everything that she doesn’t return.)
This article was originally published on 30/9/20 and updated to reflect the news the latest La Niña event.