Power was restored to most properties across Sydney and the NSW Central Coast and Hunter regions on Wednesday night, as crews continued to clean up in the wake of a wild storm.

The severe weather diverted flights from Sydney, closed roads, brought down trees and resulted in an unseasonal snow storm in the Blue Mountains.

The SES originally had more than 2000 calls for help, including people needing to be rescued after driving into floodwaters.

Others needed help with fallen trees and leaking roofs, and the SES warned people to remain cautious around debris and tree branches.

• Storm batters NSW, causes chaos
• Winter weather a thing of the past for Sydney

SES spokesman Dave Newman said it was an unusual weather event.

“It’s not very often you see a storm cell that can affect such a large area that quickly,” he said.

Superintendent Paul Johnstone from the NSW fire service said extra crews were called in to help with rescues.

“We had wires down, trees on wires, it’s an extraordinarily busy night for fire crews,” he said.

Blackheath train station pic.twitter.com/38Vq33ZLhw

— Lindsay Holmwood (@auxesis) October 14, 2014

#Storm enters #Sydney pic taken terrey hills by @nampix pic.twitter.com/CQHzm7Gk1v

— Nick Moir (@nampix) October 13, 2014

Superintendent Johnstone said lightning caused a house fire at Pennant Hills, in Sydney’s north.

About 20 firefighters fought another house fire at Guildford, but it was unclear if lightning sparked that blaze.

“This is at the height of this storm and tempest damage that we were responding to,” Superintendent Johnstone said.

“We had four fire engines respond to that fire and that house was well alight as crews arrived.”

At Ulladulla on the South Coast, 171 millimetres of rain had fallen since Tuesday morning and a 161-kilometre-per-hour wind gust was recorded at Wattamolla in the Royal National Park, south of Sydney.

#sydneystorm We had bad weather in Melbourne last couple of days, but not like this! pic.twitter.com/LtO7Efbj92 — John Adams (@jammy7000) October 14, 2014

The strength of winds sweeping the Royal National Park right now is equivalent to a category two tropical cyclone #sydneyweather — Bevan Shields (@bevanshields85) October 14, 2014

Bureau of Meteorology forecaster Chris Webb said there had been “remarkably heavy rain” in parts of Sydney during the storm.

“San Souci had 114 millimetres in three hours to 11:00pm. Marrickville, a usual suspect for flooding, 109 millimetres in four hours,” he said.

“The city had 70 millimetres.”

Ausgrid power had been restored to most homes and businesses across its network on Wednesday, despite difficult working conditions in some locations.

“Just when we’re making headway we’re receiving more reports as other wires are coming down after we started to see the wind pick up after lunch,” spokesman Anthony O’Brien said earlier in the day.

In Bundeena, he said, emergency crews located and repaired a fault on the overhead network, switching power back to most homes by about 9pm.

Weird that everyone in Sydney is scared of the rain but loves the ocean which is like ten times as wet or even more. #sydneystorm

— Adam Liaw (@adamliaw) October 14, 2014

Woah – Blackheath and Lithgow!! #SydneyStorm pic.twitter.com/UZ4eMuPkhQ — James Breko Brechney (@breko) October 14, 2014

Water is rising in the M5 tunnel near Arncliffe pic.twitter.com/e22TDyGcT9 — Daniel Kildea (@Dan_kildea) October 14, 2014

Flash flooding prompts ‘scary’ train evacuation

In the Blue Mountains, which was devastated by bushfires this time last year, a snowstorm cut power to three power stations and forced the closure of roads and the train line towards Sydney.

There were reports of up to 20 centimetres of snow falling at Oberon and Lithgow and near Bathurst, affecting road and rail access from the Central West to Sydney.

A dozen passengers had to be evacuated from a Canberra to Sydney train when it was stranded by floodwaters.

A damaged car hit by a fallen tree. Photo: AAP

SES crews helped nine adults and three children from the train at Bexley North, a Transport for NSW spokesman said.

One passenger said she was petrified.

“I looked out the window, the water was rising rapidly from the bottom level of the train,” she said.

“I went up and pressed the button to speak to the guard because we were wondering, and he could not explain what was going on, and I said ‘we need to get people off this train’.

“The water was rising and it was up to the platform, and it was quite scary.”

The snow and power outages have closed several schools in the Lithgow district, and HSC students were advised only to attend exams if it was safe to do so.

The highway has since reopened between Lithgow and Katoomba but drivers have been warned to expect delays.

Wild weather produced flash flooding in parts of Sydney. Photo: AAP

Ferries and flights cancelled as commuters battle traffic chaos

Debris and traffic light outages were also causing road problems in Sydney.

The storm also caused disruptions at Sydney Airport, with delays affecting flights on Wednesday.

The airport remained open through the storm, but 32 planes were diverted after crews decided it was too risky to land on schedule.

At the height of the storm, lightning forced airside workers to clear the tarmac.

The Cronulla Ferry Service was also cancelled due to bad weather.

Flooding closes Wollongong Hospital operating rooms

Four operating theatres in Wollongong Hospital were closed due to flooding caused by Tuesday night’s heavy rain.

The Health Department said water made its way into the theatres and the emergency department while part of the hospital’s roof was removed for construction works.

A spokeswoman said the emergency department was unaffected but some elective surgeries had been rescheduled.

Environment authorities were investigating an oil sheen on Botany Bay near the Caltex Kurnell terminal site.

Both rivers running into the bay flooded in heavy rains overnight and the Environment Protection Authority (EPA) was investigating possible multiple sources of the pollution.