Sydney has not seen in many years a bout of ferocious weather as nasty as what is hitting the city now, bringing its transport systems to a halt and forcing evacuations. Residents of southwest and central west NSW continue to deal with major flooding, with Griffith and Forbes as main focus for emergency services Thursday.

Flights were delayed at Sydney Airport due to the very bad weather, though AAP reported the exact number of affected flights was not yet clear. Still, passengers were urged to contact airlines for the latest information on their scheduled trips.

On land, transportation was not any better as nine of Sydney's 16 main railway lines, including the Eastern Suburbs, Bankstown, Inner West, Airport, South, North Shore, Western, Olympic Park and Northern lines all struggled with delays.

The floodwaters also shut dozens of roads around the city.

Superintendent Ian Krimmer told the AAP 250 firefighters from more than 50 fire stations had responded to dozens of mostly flooding-related incidents across Sydney.

Statewide, southwest and central west NSW continue to deal with major flooding.

The area around Griffith, in the state's Riverina Region, and Forbes were the main focus for emergency services Thursday, as substantial flooding escalate in the said areas.

In Wagga Wagga, where spiders have formed a bed of paddocks webs to survive a major flooding, about 600 people are still unable to return to their homes even as the floodwaters have slightly eased.

Meanwhile, the Scalabrini Retirement Village in Edmondson Avenue in Austral was evacuated Thursday morning after the nearby Bonds Creek broke its banks. About 20 people were evacuated, according to the AAP.