Persistent rain for NSW amid flood watch

A severe weather warning has been issued for the Illawarra, South Coast, Central Tablelands and Southern Tablelands, according to the Bureau of Meteorology.

Heavy rainfall is forecast for areas between Oberon, Campbelltown and Ulladulla from June 6 to June 7.

Other areas that might be impacted include Wollongong, Nowra, Bowral, Campbelltown, Jenolan Caves, Taralga and Nerriga.

Some parts of the Illawarra have already recorded falls in excess of 100mm.

There are currently three flood watches in place for minor flooding for the Hastings River, Cooks River and the St Georges Basin.

Bureau meteorologist Belinda House said that there was a low pressure trough impacting the south coast of NSW that had developed into a low pressure system.

"That low pressure system is bringing in eastern winds, primarily in the southern parts of NSW," she said.

Parts of southern Sydney, the Illawarra and down to the south coast would continue to experience persistent rain.

"It will push reasonably well into the central eastern parts of the state including Parkes and Forbes," Ms House said.

She said the rain cloud would work its way up to the Central Coast, but that was the northern extent of where NSW was going to see heavier falls.

Ms House said by June 8 rain would "continue to ease" and by June 9 "there shouldn't be too much shower activity".