“With catchments already saturated and dams at or near capacity, there is a heightened risk of riverine and flash flooding as well as landslips along central parts of the NSW coast from Saturday,” the bureau said in a statement.
“River levels are expected to rise from Saturday, with the largest impacts starting Monday or Tuesday next week.
“Wind and waves will also increase along parts of the coast from Saturday, with a risk of coastal erosion for some areas.”
The Hawkesbury and Nepean, a region that has been devastated by flooding four times in the past two years, is now preparing for the possibility of yet another flooding event this weekend.
Flooding is also expected on the Cooks River, Georges River, Woronora, and Shoalhaven.
With the school holidays beginning today in the state, State Emergency Service (SES) Commissioner Carlene York warned families to be cautious when travelling to low-lying areas.
Heavy rain started to fall over Sydney last night and BoM has warned this is “increasing”, with up to 20mm falling today.
The Warragamba Dam is currently 97 per cent full.
Weatherzone said within the deepening trough “several small-scale low pressure systems could develop” bringing powerful winds alongside heavy rain.