Heavy rain set to continue in August, in extension of July's wet weather

Australia Broadcast Center

6 days ago

Parts of southern Australia have recorded their wettest July in decades following a trio of low-pressure systems during the past week.
And as the calendar flips to August, the rain events are forecast to continue.
The month will open with yet another low forming, this time off the NSW coast, a system that has the potential to bring heavy rain this weekend.
In the meantime, a rainband will also soak WA, kicking off what is likely to become another productive month of wet weather across the country.
The recent low-pressure systems have interrupted the monotonous pattern of high-pressure that dominated southern states earlier in 2025.
Rain near the third low in the series mostly shifted into NSW later on Tuesday — however light showers under a polar air mass will still impact parts of SA and Victoria during the coming days.
For NSW though, it's the beginning of another prolonged wet spell as onshore winds off the Tasman Sea feed moisture into the slow-moving inland mass of cold air.
Falls will be heaviest near the coast during the coming days, although moderate falls are also possible over the state's northern inland.
The polar air will eventually move east and lead to the formation of a new surface low off the NSW north coast.
This next low-pressure system should initially form on Friday, before deepening into the weekend and causing rain to increase along the central and northern coastline.
The low won't reach East Coast Low status due to its mobility and only moderate strength, however the system could bring more than 100 millimetres (more than a month's worth of rain) from Friday to Sunday from the Mid North Coast, though the Hunter to eastern Sydney and the Illawarra.
While major flooding is unlikely, catchments are still relatively wet after recent rain, and rapid river rises with localised flooding can't be ruled out.
As NSW faces a weekend washout, a powerful cold front from the Southern Ocean will spread another burst of strong winds and rain through WA.
The front will make landfall on Saturday on the west coast, bringing around 20mm from Lancelin to Albany, then spread lighter rain to central and eastern WA on Sunday.
Winds will strengthen near the front, possibly triggering a warning for damaging gusts, an outcome that will become more likely if a few wintry thunderstorms develop.
While Perth's heaviest rain is likely on Saturday, post-frontal onshore winds will deliver further showers on Sunday, lifting the city's weekend total to between 20 and 50mm.
The BOM's medium range outlooks that cover the weeks ahead are now firmly favouring a wetter-than-normal August.
According to the latest BOM modelling for the fortnight from August 9 to 22, there's about a 60 to 70 per cent chance central and eastern Australia will see above-normal rain — increasing to about 80 per cent in southern Queensland and northern NSW.
Other global models concur with this scenario. The well-regarded ECMWF model from Europe is also suggesting this month is likely to be wetter than normal.
The switch from high to low pressure has delivered rain across more than two-thirds of Australia since early last week, boosting monthly rain totals to the highest in years for many locations.
Rain across WA has been particularly heavy — Busselton has received 286mm this July, more than double the average and the town's wettest month in 30 years.
Further north, Badgingarra has also recorded its wettest month in 30 years with 196mm, while Perth is having its wettest calendar month since June 2023.
For SA, Adelaide's 111mm is the city's wettest July in at least nine years, while Kimba's 111mm is nearly triple the monthly average, and the highest in July since 1956.
For Victoria, Charlton is a stand-out — 64mm is enough for its wettest July since 1996.