Last week it was a dust storm, now Sydney is going to get a good old-fashioned drenching, with the national weather forecaster issuing warnings of heavy rain, damaging winds and flash flooding for Wednesday November 28.

The Bureau of Meteorology (BOM) has predicted between 55 and 100 millimetres of rain to fall across Sydney and Illawarra in the morning and afternoon, with some localised areas expected to receive 150 to 200 millimetres in one day.

“Some places could see their month’s average rainfall in one event, potentially,” Anita Pyne, a forecaster with BOM told Broadsheet. “We’re forecasting it to be quite wet.”

The rain could arrive as early as this evening in metropolitan Sydney, will peak during Wednesday morning and afternoon before easing in the evening.

We’re told gale-force winds averaging 60 to 70 kilometres per hour will lash the city in the afternoon and evening, with peak gusts in excess of 90 kilometres per hour likely along the Sydney coast in the morning.

The wild weather is caused by a low-pressure system moving from the north-west of New South Wales, rapidly intensifying as it reaches the warm coastal waters.

Flood warnings have been issued for rivers and low-lying areas in the Sydney, Central Coast and Illawarra districts, with the forecaster warning residents against entering areas inundated with flood waters. “Don’t enter flood waters if you see them. If it’s flooded, forget it,” said Pyne.

The State Emergency Service advises residents to secure loose objects around their house and yard, such as outdoor furniture; to move vehicles under cover or away from trees; and to keep at least eight metres away from fallen power lines.