The Illawarra's weather forecast for the next 24 hours

Morgan Pumpa from the Bureau of Meteorology said the low pressure system is currently just off the NSW mid-north coast and heading south and could bring with it intense rainfall and damaging winds.

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"There's a possibility of 70 to 120mm and intense rainfall there could be locally up to 150mm if not more," she said of the Illawarra.

"Throughout today [Tuesday] we could see those heavy and intense falls and for some areas - especially along the coast and southerly facing coastal areas - could see damaging surf, which could lead to coastal erosion."

As of midday, warnings were current for the Illawarra coast for gale force winds off the coast, hazardous surf plus severe weather bringing potential heavy rain and flash flooding.

Ms Pumpa said severe thunderstorm warnings were being issued as the day progressed when very dangerous thunderstorms were detected, also noting heavy rainfall increases the potential for landslides and debris across roads (as seen across the Illawarra in the past week).

"We will see the easing of that low pressure system tomorrow, but winds will remain and possibility of hazardous and damaging surf tomorrow, before we see more settled conditions for the Illawarra on Thursday," she said.

Weather stations in the Illawarra escarpment recorded 124 mm of rain in the past day, with Mount Kembla, Dombarton and Mount Pleasant topping the list.

Mount Kembla and Dombarton recoded 124mm in the 24 hours to 10am on Tuesday, while Mount Pleasant recorded 120mm

Other weather station totals:

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