Climate double whammy could lead to widespread flooding in late winter and spring


The Indian Ocean Dipole is set to cause havoc. Picture: BOMSource:Supplied

Two separate climate systems are conspiring to bring a wet and warm end to winter, the Bureau of Meteorology has forecast.

After a calm few months, the Indian Ocean Dipole and La Nina are brewing up which could see a dramatic change in the weather over the coming months.

La Nina’s last appearance earlier this year led to massive floods across the country’s east. Widespread floods in the southeast are now a real possibility again but there is no indication yet of how serious they might be should they occur.

The Bureau’s climate outlook for August to October, released in recent days, also included a look back on the current conditions.

Last month there was record breaking rain in southwest Western Australia. Perth is expected to have had its wettest July for more than two decades.

The north of Australia was warmer than average during the first two months of winter with the southeast of the country cooler. Adelaide saw its coldest day on record on July 22 with the mercury not managing to reach even 10C.

But those chilly temperatures will soon be long gone with warmer-than-average days and particularly nights for the coming months.


The summary of the August to October climate outlook for Australia. Picture: BOMSource:Supplied

Climate drivers cranking up

The Indian Ocean Dipole (IOD) and El-Nino Southern Oscillation (ENSO) climate drivers are the causes.

Both are a measure of sea surface temperatures aided by powerful trade winds. The IOD, as the name suggests, is centred on the Indian Ocean and ENSO in the Pacific.

How these temperatures rise and fall can have a huge effect on rainfall in not just Australia but Africa and the Americas too. Generally, if it’s wetter than usual in Australia it will be drier in either or both of the other two continents.

“In the Indian Ocean, a negative IOD has developed which brings warm ocean waters to the north and northwest of Australia and typically enhances winter and spring rainfall over much of southern and eastern Australia,” said Dr Paul Feikema, a senior hydrologist with the BOM.


Warmer seas in the Indian Ocean are being pushed towards Australia increasing the possibility of rainfall Picture: BOMSource:Supplied


There is also a high chance the ENSO will turn to a neutral, or La Nina, phase also bringing rainfall. Picture: BOMSource:Supplied

That’s combining with a lowering of water temperatures in a patch of the Pacific Ocean which is crucial in the formation of positive or negative ENSO conditions – the latter of which is known as a La Nina.

A La Nina occurs when trade winds increase, hauling cooler waters from the depths of the ocean up to the surface in the eastern Pacific.

These stronger winds from east to west also push warmer seas closer to Australia. That aids in the creation of more clouds and so moisture and windier conditions for the continent.

“Some models indicate this cooling could be sufficient to reach La Nina levels during spring,” Dr Feikema said.

“However, even if La Nina levels are not reached (and ENSO remains in neutral) this cooling may strengthen the wet outlook for much of Australia. As a result, the August to October outlook suggests above average rainfall is very likely across much of the country”


It could be hotter during the day in the south and north of Australia. Picture: BOMSource:Supplied

Flooding a ‘possibility’

Already sodden catchments means that widespread flooding is a real possibility in the coming months across south eastern parts of the country.

However the increased rainfall is less likely to occur in south west WA, bringing a reprieve from the incessant rain in Perth. Southern Victoria and much of Tasmania may also miss out.


Rainfall will be heavier just about everywhere with the exception of WA and western Tasmania. Picture: BOMSource:Supplied

As for temperatures, days are likely to be warmer than average across Tasmania, Victoria, coastal New South Wales and southern parts of South Australia as well as the nation’s north.

But nights are likely to warmer across almost the entirety of the country with the exception of southwest Western Australia.

The Bureau added that Australia’s climate has warmed by around 1.44C for the 1910–2019 period, while southern Australia had seen a reduction of 10–20 per cent in cool season rainfall in recent decades.

News Related


Daniel Andrews warns Victorians not to wait for Pfizer after uncertainty around arrival of 9m doses

The Victorian government has warned people not to wait for the Pfizer vaccine, with the commonwealth advising state and territory leaders it is still unsure when more than 9m doses ... Read more »

Victorian coroner finds unjustified police pursuit resulted in death of Aboriginal man

A Victorian coroner has found that a high-speed police pursuit which resulted in the death of an Aboriginal man was not justified and called for the rules to change back ... Read more »

North Korea warns AUKUS nuclear submarine pact could trigger 'nuclear arms race'

© Associated Press North Korea says the AUKUS pact could upset the strategic balance in the Indo-Pacific. North Korea has slammed a new security pact between Australia, the US and ... Read more »

ASX posts biggest loss since February

Australia’s share market has recorded its steepest fall since February as falling iron ore prices ruined miners and Chinese property giant Evergrande teetered on collapse. © Joel Carrett/AAP PHOTOS Huge ... Read more »

Winter blast to hit NSW, bringing wind, snow and hail

A cold front will sweep across NSW this week, bringing back the frost of winter with gale-force winds, hail and snow. Temperatures are expected to plunge by up to 10 degrees Celsius on ... Read more »

Social worker advised not to give statement on Malka Leifer, court hears

A social worker has told a court she was advised against making a statement to police about former school principal and accused child abuser Malka Leifer in case she was ... Read more »

Minns forces ALP to suspend NSW CFMEU officials

NSW Labor leader Chris Minns has forced his party to suspend the membership of the CFMEU’s NSW secretary and his son who have been charged for allegedly soliciting a series ... Read more »

Federal Group pushback in Tas pokies deal

The company that has held a monopoly on poker machines in Tasmania since 1973 has challenged the proposed end date for their licence and raised worries about an increased risk ... Read more »

South Australia WON'T scrap Covid-19 restrictions with vaccines

© Provided by Daily Mail MailOnline logo There will be no ‘freedom day’ in South Australia when vaccine targets are reached, with efforts continuing to try to keep Covid-19 out ... Read more »

Vaccine supply problem solved: minister

The Morrison government has ruled out concerns Australia’s Pfizer supplies could face a shortfall next month. © Darren England/AAP PHOTOS Businesses say getting vaccinated is critical to the economy and ... Read more »

BlueScope's climate change boss warns green steel still decades off

© Provided by ABC Business Investors have been told the breakthrough technologies that will allow BlueScope to transition to green steel production is years away. (ABC Illawarra: Ainslie Drewitt-Smith) The chief ... Read more »

I took time to fully trust Hinkley: Wines

Port Adelaide star Ollie Wines says the realisation that he’s not a “silky smooth mid” and his willingness to finally trust coach Ken Hinkley played a key role in propelling ... Read more »

WA man now facing 194 child sex charges

A 23-year-old Perth man who allegedly used an online service to advertise himself as a babysitter is now facing almost 200 child sex charges. © Richard Wainwright/AAP PHOTOS A WA ... Read more »

Melbourne Demons not the only ones under AFL grand final pressure, Western Bulldogs say

The Western Bulldogs have dismissed suggestions Melbourne is under more pressure heading into Saturday’s AFL grand final at Perth Stadium, saying they too feel the weight of expectation to reward their loyal ... Read more »

Blues' AFL coaching clean-out continues

Carlton’s new senior coach will have the freedom to form his own panel of assistants after Cameron Bruce left the AFL club to join Brisbane. © James Ross/AAP PHOTOS David ... Read more »

Man pleads guilty to murder of restaurant worker Kim Chau whose body was found in Adelaide home

© Provided by ABC NEWS Restaurant worker Kim Chau’s body was found inside an Adelaide home in September 2019. (Supplied) A man has admitted to murdering an Adelaide restaurant worker at ... Read more »

Coroner urges Victoria Police to revise pursuit policy in wake of Raymond Noel Thomas's death

Raymond Noel Thomas had been driving through Melbourne’s north, on the way to the supermarket to buy chocolate, when he was spotted by officers in a marked police car. Less ... Read more »

NT becomes first Australian jurisdiction to incentivise travel for the COVID vaccinated with new $5m tourism campaign

© Provided by ABC Health Interstate tourists who have been fully vaccinated against COVID-19 are being offered incentives to book their next holiday in the Northern Territory. (Four Corners: Harriet ... Read more »

Why petrol prices are the highest they've been in nearly three years

© Provided by Daily Mail MailOnline logo Rising international oil prices have pushed Australian petrol prices to their highest level in nearly three years nationally, and to record highs in ... Read more »

Anthony Albanese loses 15kgs by giving up alcohol, cutting out carbs

© Provided by Daily Mail MailOnline logo Anthony Albanese has lost 15kgs by overhauling his diet and exercise regime in preparation for a gruelling election fight against Scott Morrison, Daily ... Read more »

Moderna COVID vaccines to arrive at Northern Territory pharmacies this week

© Getty The Moderna vaccine, which is already in use across much of the world, uses the same mRNA technology as the Pfizer vaccine. Hundreds of Moderna COVID vaccine doses ... Read more »

Queensland's borders to stay closed until 90 per cent vaccination rate

© Provided by Daily Mail MailOnline logo Queensland is set to follow in Western Australia‘s footsteps by refusing to open its borders until Australia hits a 90 per cent double-dose ... Read more »

Rusty Aussies ready for women's ODI opener

At the end of a long off-season but start of a long run-up to the World Cup, Meg Lanning admits to harbouring some nerves on the eve of Australia’s series-opening ... Read more »

One in five children aged 12 to 15 vaccinated as Moderna arrives

Pharmacists in Sydney’s hot spots received doses of the Moderna vaccine on Monday, as it was revealed one in five children aged 12 to 15 are now partially vaccinated against ... Read more »

Winds and cold snap forecast for NSW, ACT

Parts of NSW and the ACT could wake to a dusting of spring snow this week, with a cold snap and gusty winds forecast. © Steven Saphore/AAP PHOTOS Potentially damaging ... Read more »

Shares in China's Evergrande plunge again as fears of contagion grow

Shares in the embattled Chinese property company Evergrande have plunged 17% as investors weigh up whether the group’s massive debt problems could trigger a broader sell off across all financial ... Read more »

Tamworth murder victim was 'freaked out'

A young woman was “freaked out” by a man who is accused of her stabbing murder at her Tamworth home, a court has been told.  © PR HANDOUT IMAGE PHOTO ... Read more »

GF selection heartache looms for Demons

Melbourne forward Tom McDonald says it’s “horrible” to think about the selection heartache that some of his teammates will experience this week, but he’s adamant forward Charlie Spargo won’t be ... Read more »

Qld killer feared 'eternity' behind bars

A two-time killer found lifeless in his prison cell a day after the anniversary of his remand could not face “an eternity behind bars”, an inquest has found.  © Jono ... Read more »

Martial arts killer 'jealous, possessive'

A martial arts expert was motivated by “jealousy and possessiveness” when he murdered his girlfriend of about eight weeks and dumped her body in bushland, a court has been told. ... Read more »

Victorians trapped interstate to return home amid new quarantine cap

© Provided by Daily Mail MailOnline logo Dan Andrews has announced Victorians trapped in locked-down NSW for months may soon be able to return home as he flags a 500-per-week quarantine ... Read more »

Return hopes for Victorians trapped in NSW

Trapped Victorians in ‘extreme risk’ zones in NSW could soon return home. © Daniel Pockett/AAP PHOTOS Daniel Andrews says there’ll be news soon on how Victorians stranded in Sydney can ... Read more »

Koala joey and mum reunited in NSW north

An injured koala joey has been reunited with his mum after falling from a tree when an amorous male koala was aggressively pursuing his mother. © PR HANDOUT IMAGE PHOTO ... Read more »

No 'freedom day' for SA says premier

There will be no “freedom day” in South Australia when vaccine targets are reached, with efforts continuing to try to keep COVID-19 out of the state, Premier Steven Marshall says. ... Read more »

Hospital review will lock out victims: LNP

It’s been over three years since school teacher Olivia Keating went to Caboolture hospital for a caesarean and emerged with part of her bowel sewn into the wall of her abdomen. ... Read more »

Vaccine clinic at Royal Perth Show

A walk-in COVID-19 vaccination clinic will be established at the Royal Perth Show, with West Australian Premier Mark McGowan urging people to take the opportunity to get the jab. © ... Read more »

NSW govt's remaining WestConnex stake sold

The NSW government has collected $11.1 billion from the sale of its remaining stake in the WestConnex motorway and will allocate $5 billion to an infrastructure fund for western Sydney. ... Read more »

Miners' plunge resumes, ASX down 1.5pc

Iron ore miners’ plunging popularity has continued at the start of the trading week amid widespread selling on the share market. © Joel Carrett/AAP PHOTOS Huge falls for iron ore ... Read more »

ACT's swing at feds over Pfizer supplies

© Lukas Coch/AAP PHOTOS Andrew Barr says the ACT should not be treated differently to Victoria and NSW on vaccine supply. The ACT has accused the federal government of giving ... Read more »

Manly carry semi-final chip on shoulder

Taniela Paseka hasn’t stopped thinking about the last time Manly lost to South Sydney in an NRL final. © Dave Hunt/AAP PHOTOS Manly prop Taniela Paseka is desperate to right ... Read more »