A heavy band of cloud has been producing an unusual and out-of-season downpour over parts of Western Australia's north this week.
But weather forecasters say a climatic phenomenon developing off the state's north-west coast could bring more wet weather in months to come.
And it's not just WA's north.
Much of Australia, particularly the south-eastern states, is being tipped for a wet winter and spring, thanks to a climate driver known as the Indian Ocean Dipole (IOD).
What is the IOD?
The IOD affects rainfall and temperature patterns across the country, particularly during winter and spring (or the dry season if you're in tropical parts of Australia).
There are three phases of the IOD ? positive, negative and neutral. On average, each phase lasts three to five years.
While it's currently in neutral, the IOD is looking more and more likely to kick into negative gear by late winter and into spring.
If it does, it will bring with it a wetter-than-average season for much of Australia, particularly south-eastern states.
How does it work?
The IOD refers to the sustained difference between sea surface temperatures on the tropical western and eastern side of the Indian Ocean.
When the IOD is in a negative phase, the waters near Africa's east coast are cooler than usual, while the waters the the north-west of Australia are warmer.
[YOUTUBE VIDEO]Bureau of Meteorology (BOM) senior climatologist Lynette Bettio said the warmer sea surface temperatures meant more chance of rain.
"The negative IOD provides more available moisture for weather systems to tap into, so the impacts of the negative IOD are dependent on the weather systems," she said.
"For example, a north-west cloud band would deliver more rainfall in an area as broad as from north-west WA through inland parts to South Australia and Victoria."
It can also influence temperatures, often bringing cooler-than-average maximum temperatures over south-eastern Australia while maximum and minimum temperatures in Australia's far north are typically warmer than average.
The last time the IOD was in a negative phase was in 2016.
Transition blamed for dry season rain
A negative IOD event is not declared until the index remains below the threshold for at least eight weeks.
But Dr Bettio said it could still influence Australian rainfall as the event develops.
So far, the IOD index has been below the negative threshold for five weeks running.
Dr Bettio said that could be a contributor to the out-of-season wet weather in WA's Pilbara this week.
Up to 30 millimetres of rain was recorded in several Pilbara towns on Monday, with further rain forecast to reach the popular tourist destination of Broome on Tuesday.
Wet weather is typical for the south of WA this time of year, but the Pilbara and Kimberley are in their dry season, usually marked by six months of clear, blue skies.
Where is a boost in rainfall most likely?
Despite developing off WA's coastline, a negative IOD phase is most likely to bring a rainfall boost to south-eastern Australia.
Average rainfall figures from past negative IOD phases show Victoria and New South Wales are given the biggest boost in rainfall (indicated in blue shading on the above map).
Large areas of Queensland, South Australia, Hobart, the eastern half of the Northern Territory plus the Pilbara, Gascoyne and Goldfields regions of WA also have above-average rainfall (indicated in green).
No part of Australia experiences below-average rainfall.
WA's south to miss out
As parts of WA's south clean up the trail of destruction caused by intense downpours over the weekend, it may be hard to believe, but the new phase of the IOD is unlikely to have any impact for the state's most populated region, the South West.
[tweet: Denmark wet weather]In fact, many of the major climate drivers, such as La Nina and El Nino, yield little influence over the region.
"In the cool season rainfall predominantly comes from the passage of cold fronts, and it is rare that they are far enough north to channel the moisture across the southwest," Dr Bettio said
But after one of the wettest autumns in decades, particularly for parts of WA's Central Wheatbelt and Great Southern, it is unlikely the region will be desperate for the extra rain this year.
© ABC 2021
13:11 AEST At least 67 people have been killed in the western Indian state of Maharashtra by torrential monsoon rains that have caused landslides and flooded low-lying areas, cutting off hundreds of villages.