A torrential downpour is lashing Sydney and other parts of NSW with the rain expected to last throughout the week as the humidity hits 90 per cent.
The Bureau of Meteorology issued a severe thunderstorm warning on Tuesday, forecasting heavy rainfall for residents in parts of the Blue Mountains-Hawkesbury region, Gosford-Wyong and western Sydney.
Severe thunderstorms were detected on the weather radar near suburbs including Hornsby, Parramatta and Sydney Olympics Park.
The heavy rainfall could lead to flash flooding in some areas as humidity soars to 90 per cent.
Parts of western Sydney have already received over 65mm of rainfall since 9am on Tuesday as the wild weather continues.
Wyong in the Central Coast recorded 143mm of rain in the same time frame.
Storms with heavy rainfall will last for the coming days with intense rainfalls forecast, the BoM said.