How the storm hit 

• The "once in a decade" storm developed after a relatively weak low-pressure trough on the east coast was joined by an upper level trough of cold air that had moved in from Victoria. When the two systems combined, a cyclonic rotation was created as the warm moist air along the coast interacted with the cold upper-level air inland.
• The strength of the storm was driven by the steep gradient between the warm air over the Tasman and cool air at upper levels of the atmosphere, making for a classic east coast low set-up.
• On Tuesday, the storm battered the Metropolitan, Hunter and Illawarra districts with destructive winds, heavy rain and damaging surf.

Where the storm is headed

• By Wednesday morning, the storm had split into two centres as its strength weakens.
• The main core of the low was located about 100 kilometres off the Central Coast and will remain largely stationary as it weakens.
• Another belt of storms is headed for the city on Wednesday, dumping another 15-50mm of rain, with the heaviest falls likely to be in the eastern suburbs.
• Another smaller low has developed east of Batemans Bay to Sydney's south, and will bring strong winds and heavy rain to the Illawarra and the South Coast later on Wednesday.

The toll

• Three people were killed in Dungog on Tuesday after flash flooding roared through the central Hunter township, sweeping away at least three houses and damaging many others. 
• 25,000 Sydney homes and businesses went without electricity on Tuesday night. A further 100,000 Ausgrid customers in Newcastle and the Hunter region were also without power on Tuesday evening, and 75,000 customers Central Coast also experienced black outs
• On Wednesday morning, the State Emergency Service said it had handled 7900 call-outs since Monday and rescuers had saved 47 people from floodwaters. 
• Cruise ship Carnival Spirit, carrying 2500 passengers and 1500 crew, was expected to dock at Circular Quay about 10am on Wednesday, after spending Tuesday stranded outside Sydney Harbour waiting for the rough conditions to ease.

Stats on the storm 

• By 7.30am on Wednesday, 220mm of rain had fallen on the Sydney CBD since 9am on Monday, making it the wettest two-day spell in 18 years. 
• It has also been Sydney's windiest spell, with three consecutive days of damaging winds above 90km/h. On Tuesday, Sydney endured gale-force winds, topping 130km/h.
• Waves off Sydney's coast hit 15 metres on Tuesday, sending waves of up to three metres crashing on to Sydney's beaches. 
• By 7.30am on Wednesday, water from Manly Dam was spilling over the dam wall, but there was no immediate threat to the surrounding community. 

Transport 

• NSW Premier Mike Baird has urged Sydneysiders to stagger their travel to and from work on Wednesday, delay unnecessary travel and avoid travelling during peak times if possible.
• More than 250 traffic signals between Sydney and Newcastle were out of service on Wednesday morning.
• Many other roads were affected by flooding, fallen trees and wires.

Sydney road closures

• Wakehurst Parkway - closed at North Narrabeen.
• Oxford Falls Road - closed at Oxford Falls.
• Audley Weir - closed in the Royal National Park.
• Liverpool Road - closed westbound in Enfield.
• Local roads also remain closed in many other suburbs including Marsden Park, Shanes Park, Rouse Hill, Schofields, Annangrove, McGraths Hill, Cattai, Maraylya, Glenfield.

Newcastle/Hunter road closures

• Industrial Drive - closed northbound in Tighes Hill.
• Main Road - closed between Heddon Greta and Gillieston Heights.
• The Esplanade - closed in Newcastle.
• Northcott Road - closed southbound at Adamstown Heights.
• Cessnock Road - closed in Abermain.
• Local roads also remain closed in many other suburbs throughout Newcastle, Singleton, Port Stephens and Maitland areas.

Trains

• Central Coast & Newcastle Line - buses are replacing trains between Wyong and Hamilton.
• Hunter Line - closed between Hamilton and Dungog/Scone due to flooding. A limited bus service is running.
• South Coast Line - buses are replacing trains between Kiama and Oak Flats.
• T3 Bankstown Line​ - trains now operating between Campsie and Sydenham after earlier flooding.
• T2 Inner West Line - Lewisham underpass is flooded. As a result, a shuttle bus is running back and forth between Lewisham and Summer Hill.

Ferries

• The Circular Quay to Manly ferry is now operating; passengers should allow additional travel time.
• Parramatta River ferries are not operating between Parramatta and Meadowbank due to overflowing at Parramatta Weir; buses are operating instead.
• The Stockton to Newcastle Ferry is now operating.
• The Cronulla to Bundeena, Palm Beach to Ettalong and Empire Bay to Woy Woy ferries are not operating.

School closures 

• 100 public schools across NSW are closed on Wednesday. The full list is here: http://www.dec.nsw.gov.au/about-us/news-at-det/bushfire-safety