By Brendan Kearns
The intense weather event is lashing down on NSW, causing flash flooding and destructive winds.
Transport for NSW Coordinator-General Howard Collins warned commuters to stay home if they had that option.
鈥淭he advice for people using our public transport and roads is you don鈥檛 have to travel, stay indoors as your recommendations are,鈥 Mr Collins told the ABC.
鈥淚f you鈥檙e an essential worker and you鈥檝e got to get home or to work, please take your time.
鈥淭hey may well be more disruption. So if you are planning to get home, leave early. Take your time. Don鈥檛 leave it till late in the evening because that鈥檚 when disruptions occur.鈥
The storm has caused mass disruptions across the state鈥檚 transport network.
More than a dozen roads have been flooded in areas including Byron Bay and Jervis Bay.
In the state鈥檚 capital the Pacific Highway has flooded in St Leonards with two of four southbound lanes closed.
Also in Sydney鈥檚 suburbs Euston Rd has flooded in Alexandria with one southbound lane closed.
Serious flash flooding has swept through Newcastle with Coxs Ln and Mungo Brush Rd flooded and a warning issued to drivers.
鈥淣ever drive through floodwater, avoid the area, stay away,鈥 the warning read.
The affected areas include the Mid North Coast, Hunter, Central Coast, Sydney, the Illawarra and South Coast.
Anyone preparing to commute or drive through those areas has been urged to stay informed and most importantly drive to the conditions.
Mr Collins said: 鈥淲hether you鈥檙e travelling by car or catching public transport please allow plenty of extra time to get to your destination.
鈥淒on鈥檛 drive, walk or cycle through flood waters, watch out for storm debris on the road, and if weather conditions become too severe, find a safe place to stop and wait until it passes.
鈥淧assengers on public transport should take the time to hop online and check timetables before they set off and stay across any updates during their trip.鈥
Transport for NSW warned travellers to expect delays and disruptions as the extreme weather lashes the region.
Multiple ferry services have been cancelled in Sydney with F9 Watsons Bay Wharf closed due to high winds.
Replacement buses are operating.
Mr Collins warned that there is 鈥渁 lot of risk of the harbour going above four metres鈥, which may mean that ferry services continue to be suspended.
NSW Maritime has advised boaters to stay ashore and avoid any non-essential boating amid the hectic weather.
NSW Maritime Executive Director Mark Hutchings said boat owners should be prepared for dangerous weather to continue to Thursday morning.
鈥淲e are advising everyone to stay off the water over the next couple of days, and boaters should check moorings and secure any items on board,鈥 Mr Hutchings said.
鈥淟arge and powerful waves are expected, which can cause coastal bars to change quickly and without warning, and pose a serious risk to those on the water.鈥
Air travel has also been significantly disrupted with Sydney Airport moving to single runway operations.
This is expected to lead to delayed and cancelled flights at least until 11pm Tuesday, and possibly into Wednesday.
At least 20 flights have been cancelled across airlines, with guests encouraged to keep an eye on the status of their flights.
In a statement a Virgin Australia spokesman said the airline regrets the 鈥渋mpact of this on guests鈥 travel plans鈥 and it is working to help travellers reach their destination.