Severe Thunderstorms and Flash Flooding Threaten Queensland and NSW

Severe thunderstorms are forecast to continue across Queensland and New South Wales over the next three days following a destructive weather outbreak that left tens of thousands of homes without power.

A band of rain, flash flooding, and possible hail will threaten millions of Australians across both states, according to Bureau of Meteorology warnings. Saturday brought widespread rain across the Central Interior and northwest, where 30mm fell and a few locations recorded over 50mm, meteorologist Robert Urbaniak said.

Storms developed in the far southwest, the southern interior, and the Gulf Country before tracking east over the afternoon and evening. Zeta, west of Longreach, recorded 52mm of rainfall in under two hours, which Urbaniak noted was close to severe thresholds.

Supercell Thunderstorm Causes Widespread Outages and Damage

The latest weather warnings follow an intense supercell thunderstorm that ploughed across Brisbane’s south earlier in the week, leaving more than 80,000 households without power. The vast majority of those outages hit the Logan area, where the storm uprooted trees, tore roofs off houses, and downed more than 400 powerlines.

Senior meteorologist David Crock described Wednesday’s weather as a classic spring thunderstorm outbreak for south-east Queensland.

“That separates the updraft of the thunderstorm where it's taking in that moist, humid, warm air from the downdraft of the thunderstorm which is where the rain is falling and the wind's coming down through the storm,” senior meteorologist David Crock said, explaining that supercell storms can live much longer than average thunderstorms because rotation prevents the storm from choking.

“They get a bit of extra strength and they start rotating. It’s similar to the sort of physics that makes a cricket ball swing,” Crock said, according to the Australian Broadcasting Corporation. South-east Queensland remains a hotspot for such storms due to local topography and high moisture levels.

In the 24 hours leading up to Sunday morning, the SES received 34 call-outs, with 74 per cent of tasks involving structural repairs and tarping. A Queensland Police spokesman said many requests stemmed from damage sustained earlier in the week. Logan recorded 22 requests for assistance, followed by the Fraser Coast with four, Gladstone and Ipswich with two each, and single requests in the Lockyer Valley, Sunshine Coast, Brisbane, and Townsville.

Warning Areas for Sunday and Monday

Meteorologists warn that Sunday brings a renewed threat of severe storms for areas southeast of Longreach, including Charleville, Blackall, Clermont, Emerald, Biloela, St George, Roma, Toowoomba, Brisbane, and the Gold Coast. Peak risks are expected between 3pm and 5pm, bringing heavy rain, damaging winds exceeding 90km/h, and hail.

“They'll start from around midday. Obviously, there's still thunderstorms ongoing in the north. But this is a new batch of thunderstorms for today,” meteorologist Robert Urbaniak said.

In New South Wales, severe storms are also expected to reach Sydney on Saturday evening ahead of an even larger storm day on Sunday. Meteorologist Sarah Scully warned that Coffs Harbour and Port Macquarie face potential high-end supercell storms on Sunday with giant hail greater than 5cm in diameter and destructive wind gusts exceeding 120km/h.

“Within this area, you could see giant-sized hail, with a diameter greater than 5cm, as well destructive wind gusts – in excess of 120 kilometres per hour,” Scully said.

On Monday, Gympie, Brisbane, south-east Queensland, and northern New South Wales will face continued thunderstorm risks. Emergency services advise residents to secure outdoor furniture, park vehicles undercover away from trees, and monitor official weather updates.