About 300 square metres of roofing has been peeled off a retirement village in Stockton.

Residents and staff at Westcott Presbyterian Aged Care had to be evacuated just after 10am when winds ripped open a hole in the building's roof.

Three Fire and Rescue units, police, paramedics and the State Emergency Service were all on scene on Friday morning. The incident has also caused traffic delays around Fullerton and Hereford streets.

Paul Sadler, CEO Presbyterian Aged Care, confirmed the roof over the Ibis Wing had been blown off and thankfully no one was injured during the incident.

"Thirty residents in the upstairs Ibis Wing have been moved to safety in other parts of Presbyterian Aged Care Wescott," he said.

"We are liaising with family members and the emergency services to arrange temporary accommodation for these residents. Wescott will be able to house some of them in other rooms, and we are currently making arrangements with other local residential care providers for the interim accommodation of the remaining residents."

Thirty elderly residents were sitting in their rooms in a Stockton aged care facility when wild winds tore the roof off above their heads.

It was "very, very lucky" that no-one was injured when 300 square-metres of corrugated iron and concrete ripped from the top of Wescott Community Care, a senior paramedic said.

"It was just by sheer luck that the 30 residents who were attached to that wing were not injured and no injuries were sustained to any members of the public," NSW Ambulance Inspector Joel De'Zuna said.

"We still have bits of material flying off. Any of that could have hit somebody and caused damage."

Sonja Wennekes, who was working behind the bar at the Boatrowers Hotel across the road from the aged care facility, said the sound of the roof ripping off caught her attention.

"We didn't see anything at the beginning because it came from the other side but we heard it," she said.

"It sounded like a plane coming in to land on the floor in here."

Fire and Rescue NSW Inspector Brett Crotty said it was lucky no-one was in the street near the aged care facility when the incident took place.

"It was very dangerous when [fire crews] first got here," he said.

"There was a lot of debris and roof sheeting, tiles had come off the roof as well so it was quite a dangerous situation to start with."

A portion of Hereford Street has been closed to traffic while police, Fire and Rescue NSW, paramedics and State Emergency Service crews attend the scene.

In a rare occurrence, all Stockton-Newcastle ferry services have been cancelled.

"Buses are replacing the Newcastle to Stockton ferry which is currently not running due to adverse weather conditions," a Transport for NSW travel alert said.

Keolis Downer said it would monitor weather conditions throughout the day, but buses would likely replace ferries into the afternoon.

Part of a roof has also come off an apartment block in Tyrell Street Newcastle. Emergency services have shutdown the street until the site can be cleared.

Police have also issued a safety warning for anyone travelling to Barrington Tops hoping to see snow overnight. Severe winds have already pummelled the area, scattering debris and causing the collapse of a large old tree at the Victoria Hotel, Moonan Flat.

The Bureau of Meteorology issued a severe wind warning for the region on Thursday.

A series of cold fronts are expected to cross southeastern NSW from Thursday until Sunday, generating vigorous westerly winds.

Winds averaging 60 to 70 kilometres per hour with peak gusts in excess of 90 are expected for the high country about the Barrington Tops. In Newcastle and the rest of the Hunter damaging winds are expected from Friday morning, averaging 60 to 70 kilometres per hour.

Winds are also causing problems at Sydney Airport where some 20 flights were cancelled or delayed by 10am on Friday and the airport was down to a single runway.

The majority of flights are still leaving on time. The airport is urging people to contact their airline and arrive with plenty of time to spare. Newcastle Airport was only showing one cancellation as of 11am Friday.

The State Emergency Service advises that people should:

* Move vehicles under cover or away from trees.

* Secure or put away loose items around your house, yard and balcony.

* Keep at least 8 metres away from fallen power lines or objects that may be energised, such as fences.

* Report fallen power lines to either Ausgrid (131 388), Endeavour Energy (131 003), Essential Energy (132 080) or Evoenergy (131 093) as shown on your power bill.

* For emergency help in floods and storms, ring your local SES Unit on 132 500.

While you're with us, did you know Newcastle Herald offers breaking news alerts, daily email newsletters and more? Keep up to date with all the local news - sign up here.

IN NEWS: