Sydney, NSW weather forecast: 90mm of rain predicted

A rapidly deepening weather system is set to lash the NSW coast this week, with Sydney set to cop a drenching tomorrow.

A rapidly intensifying weather system, known as a “bombing low”, is set to impact Sydney and parts of the New South Wales coast from tomorrow, bringing torrential rain, damaging winds, and potential flooding.

The system, which began forming off the southern Queensland coast on Sunday night, is expected to develop into an east coast low by Tuesday.

As the pressure in the system drops rapidly, it will intensify, leading to wind gusts of up to 100km/h and rainfall totals exceeding 200mm in some areas, including Sydney, the Hunter Valley and the Great Dividing Range.

Residents in NSW are being urged to prepare now as a powerful “bomb cyclone” bears down on the state.

The Bureau of Meteorology’s Daniel Hayes said “bomb cyclone” - or “bombogenesis” - described a low pressure system that formed “very quickly”, causing pressure to drop significantly within a short period of time.

Sydney is predicted to cop up to 90mm of rain on Tuesday, and up to 35mm on Wednesday.

Sydney could cop more than 200mm of rain in the next week, and parts of the Mid-North Coast could record up to 300mm.

NSW SES has now activated all 11,000 of its volunteers in preparation for the wild weather, and are urging members of the community to get ready.

NSW SES Acting Assistant Commissioner Allison Flaxman said property damage from destructive winds and flash flooding were significant risks amid the “dynamic” weather system.

“People should prepare now by tying down any loose items around their homes so they don’t become projectiles and damage property in the forecast wind,” she said.

“Be alert today so you’re safe tomorrow, by understanding your risk and planning what you will do and where you will go if you are impacted by flash flooding or riverine rises.

The Bureau of Meteorology warns that the combination of heavy rainfall and strong winds could lead to flash river flooding, as well as widespread tree damage due to saturated soils.

What NSW can expect tomorrow. Picture: Sky News

The system, which began forming off the southern Queensland coast on Sunday night, is expected to develop into an east coast low by Tuesday. Picture: Rohan Kelly

Bureau of Meteorology meteorologist Angus Hines advised residents to monitor forecasts closely and prepare for potential disruptions, including dangerous coastal conditions and hazardous driving conditions

Even in areas away from rivers Mr Hines said there was the risk of flash flooding where the deluge overwhelms drainage systems as well as dangerous driving conditions.

“We could see flooding anywhere and that can mean inundation of homes, businesses, properties and roads and streets,” Mr Hines said.

The system is forecast to begin moving eastwards by Thursday, but its impacts are expected to be felt throughout the week.

This latest system arrives on the heels of a record-breaking polar blast that plunged much of southeastern Australia into the coldest June temperatures in decades.

Canberra recorded subzero minimums last week, while regional NSW towns experienced widespread frost and icy mornings.

Originally published as Sydney, NSW weather forecast: 90mm of rain predicted