Parts of NSW, including Sydney, have been warned to expect more than 100 millimetres of rain in coming days, as fresh deluges descend on eastern Australia.

The latest weather warning comes as a tropical low off the coast of Darwin and monsoonal rain in far north Queensland are expected to bring large volumes of rainfall to already sodden regions in the country’s north.

The Bureau of Meteorology said some areas south of Darwin could experience up to 500 millimetres of rain by Wednesday, with widespread totals elsewhere in the region of 200-300 millimetres.

A severe weather warning has been issued for the Top End in the Northern Territory, including Darwin and the Tiwi Islands, with damaging wind gusts and monsoon squalls also expected.

Senior meteorologist Angus Hines said the combination of the low-pressure area and predicted thunderstorms could lead to damaging winds.

“We could see damaging wind gusts in excess of 90km/h through the course of Sunday and into Monday as it stays windy into the new week,” he said on Sunday.

“Some areas might see as much as 500 millimetres through this part of the country. with much more widespread totals in the region of 200-300 millimetres.

“As well as that there will be extensive rainfall of 100 millimetres-plus through much of Northern Territory, a lot of north Queensland as well.”

Meanwhile, forecaster Weatherzone said “significant rainfall” loomed for the NSW coast and adjacent inland in coming days.

“[There is] the potential for deluges and flash flooding across the metropolitan Sydney, Illawarra, and Central Coast regions,” it warned on Sunday.

“A coastal trough, coupled with a highly moist south-easterly flow, is set to intensify showers … along the NSW coast and adjacent inland areas.

“Monday’s rainfall holds the potential for deluges, raising the risk of flash flooding during the morning and afternoon. This may result in a notable disruption to workers’ commute as many people return to the office after Christmas breaks.”

Weatherzone said regions north of Batemans Bay were likely to be hardest hit, with parts of the Illawarra, Sydney Metropolitan and Central Coast most at risk of heavy falls. Up to 80 millimetres of rain is expected in these areas throughout Monday – although thunderstorms could boost those totals to as much as 120 millimetres.

Further north, a monsoon trough spanning from Western Australia across to the far north Queensland coast is expected to bring heavy rainfall to an already saturated region.

Residents in far north Queensland are still reeling from heavy rainfall and flash flooding in December caused by ex-tropical cyclone Jasper last.

The bureau forecast totals of 100-200 millimetres of rain and frequent widespread thunderstorms through the week with the risk of flooding.

A severe weather warning North Tropical Coast, Tablelands, Herbert and Lower Burdekin forecast districts was cancelled early on Monday.

There are flood watches for parts of the NT’s western Top End and areas to the south-west, west and north of Cairns in Queensland.

“As we track the rainfall across these river catchments, they may well respond with flood responses through the course of the next couple of days,” Hines said.

-with AAP