THE heavy rainfall following cyclone Oswald which has caused widespread flooding in Queensland is forecast to hit Sydney on Monday as long-weekend holidaymakers return to the city.
Experts describe the flooding and tornadoes battering the east coast as the worst they have seen in 30 years.
The weather bureau issued a severe weather warning for parts of the state with heavy rainfall and winds of up to 140 km/h expected. Up to 300 millimetres of rain could fall in areas of Sydney over 24 hours from Monday morning.
The Queensland Premier, Campbell Newman, said central Brisbane was expected to flood on Tuesday and Wednesday but the levels will not be as devastating as they were in 2011.
If current projections play out, 3600 residential properties will be affected in Brisbane and of those, 2100 are unit dwellings where only ground floor flooding is expected. About 1250 businesses are also expected to be affected while about 50 homes are projected to be inundated in the Ipswich suburb of Goodna.
Mr Newman called in the army to help with the crisis, as Bundaberg prepared for the worst flooding in more than a century.