A major rain event is building across Australia this week, with forecasters warning of some of the heaviest falls in months in some regions as a slow-moving system drenches large parts of the country.
Heavy rain, thunderstorms and strong winds are expected to affect every state and territory over coming days, with flooding possible in parts of NSW and Tasmania as upper-level troughs and low pressure systems move across the nation.
According to Weatherzone, the active weather pattern will be driven by a series of slow-moving upper-level lows, creating unstable conditions capable of producing widespread rain, storms and gusty winds.
The wet weather is expected to stretch across South Australia, Queensland, NSW, Victoria, Tasmania, the ACT and the southern Northern Territory from Monday through to midweek before shifting further east later in the week.
Bureau of Meteorology meteorologist Jonathan How warned a “significant rain event” was developing across eastern Australia.
“Heavy rainfall is likely and some areas could see their best rainfall in months,” Mr How said on Monday.
Forecast models indicate much of southeastern and eastern Australia will receive rainfall between Monday and Friday night, although totals are expected to vary significantly depending on where thunderstorms and rain bands develop.
Mr How said rainfall would initially focus on South Australia, western Queensland, western NSW and Victoria before consolidating into a broader rain band from midweek.
“From midweek, though, those showers do consolidate into a rain band and the focus shifts towards the east into central and South East Queensland, eastern NSW and down towards eastern Tasmania,” he said.
Weatherzone said eastern and northern NSW, along with eastern Tasmania, had the highest risk of heavy rainfall and flooding, while significant falls were also expected in parts of the ACT, eastern Victoria and southern Queensland.
Southern Queensland could receive up to 100mm of rain extending from coastal areas into inland regions including the Darling Downs, according to the bureau.
In NSW, rainfall totals could exceed 100mm across the North West Slopes and Central West, while coastal areas may receive more than 150mm depending on the development and movement of a low pressure system off the coast later this week.
“And through these parts of the country it has been an incredibly dry autumn so far,” Mr How said.
Eastern Tasmania could also receive totals approaching 100mm.
The bureau warned severe thunderstorms were likely across inland NSW, the NSW south coast and South East Queensland over coming days, bringing risks of heavy rainfall, damaging winds and large hail.
“The main risk will be for heavy rainfall, but for southeast and central Queensland there is the additional risk of damaging winds as well as large hail,” Mr How said.
Authorities are also closely monitoring flood risks in already saturated areas, particularly in northeast NSW and South East Queensland.
Weatherzone said eastern parts of NSW, Victoria and Tasmania were also likely to experience increasing winds and dangerous surf conditions later in the week as a Tasman Sea low developed.
Western Australia is also set to be impacted by two separate systems this week.
A cold front is expected to bring rain, thunderstorms and blustery winds to the southwest on Wednesday and Thursday before a second and potentially more severe low pressure system arrives over the weekend.
That system could deliver heavy rain, damaging winds and severe thunderstorms from Saturday into Monday.
While the weather could create dangerous travel conditions and flash flooding in some regions, Mr How said the rain would also provide relief for drought-affected agricultural areas.
“For inland parts of the country, particularly for agricultural areas, this rain will be very welcome, particularly given how dry it has been so far this autumn,” he said.
The bureau has urged residents to monitor forecasts and warnings as conditions evolve throughout the week.
“If you are across parts of eastern and southeast Australia over the next few days, with significant rain coming, do check for the latest forecasts and warnings,” Mr How said.
