East Coast Low could hit the Hunter with Heavy Rain and Damaging Winds

28 June 2025

newy.com.au – Residents in Newcastle and across the Hunter region may be in for significant weather event next week, as meteorologists warn of a potentially intense east coast low developing off the New South Wales coast. The system is forecast to form late Sunday 29 June 2025 into Monday, with peak impacts expected between Tuesday and Wednesday.

According to forecaster Josh from Cyclones O, two major streams of moisture, one from North Queensland and another from the Coral and Tasman Seas will converge off the southeast Queensland coast, creating ideal conditions for the formation of a low pressure system. The system is expected to intensify rapidly on Monday night and reach full east coast low status by Tuesday morning.

“This system is going to get its act together very quickly through Monday night into Tuesday morning,” Josh said, noting that the worst of the weather is likely to occur between midday Tuesday and midday Wednesday. During this window, areas from Wollongong to Taree, including Newcastle and Gosford, are expected to bear the brunt of the storm.

Forecast modelling indicates the low will be situated offshore from around Newcastle to Taree at its peak, placing the Hunter region squarely in the path of the system’s most severe impacts. Depending on the system’s trajectory, Newcastle could see rainfall totals of up to 200 millimetres across Tuesday and early Wednesday, while Gosford may receive up to 225 millimetres. Sydney’s northern suburbs could also see totals near 200 millimetres, tapering to around 100 millimetres in the west.

According to ABC meteorologist Tom Saunders, this system meets the criteria for a “bomb cyclone”, a rapidly deepening low-pressure system undergoing “bombogenesis”, where the central pressure drops more than 14 hectopascals in 24 hours in this region. “Next week’s low is predicted by modelling to deepen between 22 hPa and 24 hPa in a day, easily passing the weather bomb criteria,” Saunders stated.

Jonathan How, meteorologist at the Bureau of Meteorology, spoke about the unpredictability of coastal lows. “As with all low pressure systems off Australia’s east coast, the impacts will depend on how close the low does get to the coast and also how long it does stay there for,” he said. He warned that if the low remains closer to the shoreline, the risk of flooding, wind damage and erosion would increase significantly.

“Rain will increase across central parts of New South Wales, including for Sydney, the Illawarra and also the Hunter,” How said, pointing to Tuesday as the key day for heavy rainfall and damaging winds in the region. “Very strong to possibly damaging winds wrapping around the southern flank of the low” are expected to impact coastal and adjacent inland areas.

Coastal areas can also expect destructive wind gusts. Peak gusts onshore from Sydney north to Nelson Bay may exceed 100 kilometres per hour, with offshore winds potentially reaching 130 kilometres per hour. Offshore near Lord Howe Island, modelling has suggested wind gusts as high as 190 kilometres per hour, a figure described by Josh as “something I have never seen from an east coast low before.”

“Out on the water we are also expected to see dangerous coastal conditions,” How said. “These wave heights will likely exceed 3 to 6 metres depending on where the low pressure system is.” The Bureau warns this may lead to coastal erosion, even after the low moves into the Tasman Sea.

While not currently forecasting major flooding, the volume and intensity of rainfall could cause localised flooding, particularly in low lying and flood prone areas around the Hunter, Gloucester, Manning and Taree river systems. “It really kind of looks like a bit of a touch-and-go situation,” Josh said.

Warm sea surface temperatures, sitting between 22 and 23 degrees Celsius off the NSW coast, are providing additional fuel for the system to rapidly strengthen. “That’s going to mean there’s going to be plenty of available moisture and energy coming off the oceans that this system can make the most of, and let me tell you, it will,” Josh said.

Another key factor enhancing the storm’s power, according to Saunders, is the contrast between the warm ocean air and colder polar air, helping intensify convection and rainfall.

How added that damaging winds could bring down trees, topple power lines, and impact beach and foreshore activities. “We may see damage to trees and property as well as power lines being toppled over,” he said. “Heavy rainfall is possible depending on where that low pressure system does form, and this may lead to flash flooding as well as riverine flooding.”

If the system meets further criteria, such as maintaining a closed circulation, lingering within 200 kilometres of the coast for 12 hours, and exhibiting a pressure gradient of at least 4 hPa per 100 km, it may be classified as the first official East Coast Low (ECL) since 2022.

The system is expected to move offshore by Thursday 3 July, gradually weakening as it tracks towards New Zealand. However, forecasters will continue to monitor its development closely, with updates anticipated over the coming days. “It is important to stay up to date with the latest forecasts and warnings through the weekend and also into next week,” How advised.