Parts of New South Wales have been hit by near-record rainfall as a weather system moving across the state is giving Sydney a wet end to the month.It comes as the SES has warned large parts of the state, including Sydney, to prepare for the risk of flash floods.Authorities warn rainfall will shift from inland areas to parts of the NSW Mid North Coast, and Hunter Valley regions, and could extend into Greater Sydney and the Illawarra.LATEST: Warning of flight