The NSW State Emergency Service (SES) has responded to more than 300 incidents across the state in the past 24 hours, after widespread heavy rainfall impacted Sydney, the Blue Mountains and the Central Coast.
The Bureau of Meteorology recorded 152 millimetres of rain in the Hawkesbury the 24 hours to 9am Monday.
NSW SES volunteers worked overnight to assist with leaking rooftops and fallen trees, particularly across the Northern Beaches and Western Sydney. At Castlehill, a large tree fell on a property causing significant damage.
During this afternoon and evening, heavy rainfall is expected to move north to the Mid North Coast and Northern Rivers. NSW SES has prepositioned personnel and assets ahead of the expected rain.
NSW SES Assistant Commissioner Nicole Hogan ESM, said the rainfall forecast for the next 24 to 48 hours could cause flash flooding in northeast parts of the state.
"The bureau has forecast rainfall totals of 100 to 200 millimetres in some areas, but it is variable with thunderstorms, so we ask people to monitor conditions and warnings," Assistant Commissioner Hogan said.
"It's school holidays and we know people are travelling to see family and friends, but we urge you to never drive through floodwater and to plan your route."
Assistant Commissioner Hogan also advised people camping in low lying areas, or planning to camp this week, to know their flash flooding risk.
"Please be safe when camping or caravaning near rivers, as flash flooding can occur very quickly and without warning," she said.
"Monitor the conditions and avoid camping in low lying areas. Should river rises or flash flooding occur, seek higher ground."
There are also warnings for minor riverine flooding in southern and northern NSW.
In Southern NSW, minor flooding on the Murray River at Perricoota and Koondrook is expected to continue for several weeks. The NSW SES is working with local landholders to inform them of their risks.
Minor flooding is also occurring in the state's north at the Warrego River in Barringun and Fords Bridge, and on the Paroo River at Willara Crossing.
For emergency help in floods and storms, call the NSW SES on 132 500. In life threatening situations, call Triple Zero (000) immediately.
