A major bushfire in the New South Wales’ Hunter region remains at an 'Emergency' warning level tonight, while another two have been downgraded as winds hamper firefighters' containment efforts.

North of Sydney, the fire in the Salt Ash area near Port Stephens has increased in strength due to strong wind gusts.

The “erratic” blaze has moved quickly towards Tanilba bay, where firefighters are ready to undertake property protection.

People in the Tanilba Bay, Mallabumla and Lemon Tree Passage areas are advised to seek shelter as the fire approaches.

Firefighters are assisting in the relocation of people and caravans to the Lemon Tree Passage boat ramp, Henderson Park.

Oyster Cove Road and Lemon Tree Passage Road are both closed.

People affected in both areas have been urged to put their Bushfire Survival Plans into action immediately.

An earlier ‘Emergency’ fire at Woodstock in the Mount Kingiman area, near Ulladulla on the NSW South Coast, burnt out of control and tore through more than 4000 hectares of land.

The NSW Rural Fire Service earlier upgraded the fire's warning level and warned residents in the area that strong winds have affected the fireground.

After 6pm, the fire was downgraded to an 'Advice' level alert as firefighters gained the upper hand and managed to slow its spread.

Meanwhile, a third bushfire burning around the town of Tabulam, west of Ballina on the NSW Far North Coast, has also been downgraded to an ‘Advice’ level after sitting at an ‘Emergency’ level throughout the day.

The fire crossed the Clarence River, forced the closure of the Bruxner Highway at the Tabulam Bridge.

Firefighters in seven regions across New South Wales are today battling the strong winds as over 70 bushfires rage across the state.

The NSW RFS has warned of “Very High” fire dangers tomorrow for the Greater Sydney, North Coast, Northern Slopes, New England and Far North Coast regions. A total fire ban remains in place.

Wind speeds of up to 40km/h are also expected to continue tomorrow with areas in northern NSW expected to see possible speeds higher than that.

Inspector Ben Shepherd from the NSW RFS earlier told the TODAY Show that residents should be prepared for the threat of a quickly-moving blaze.

“Have that discussion this morning about what you’ll do in the event that a fire actually threatens,” he said.

“Also, do some preparation around your property, because we’ve seen over the last week that fires can start quickly and spread rapidly and impact on homes with little or no warning.”

Backburning operations have been undertaken over recent days to limit the threat to homes after fires destroyed two homes and 16 buildings in the state’s south-west this week.

Four of the largest fires have all been downgraded to an ‘Advice’ warning level, but remain burning.

A bushfire in Ramornie has burnt around 350 hectares of land while another in Pinkett has torn through more than 1500 hectares.

The fire burning at Bemboka in the Bega Valley has burnt over 4000 hectares and the Ellangowan bushfire has affected almost 2000 hectares of land.

The increased containment efforts come as a NSW RFS contracted waterbombing helicopter pilot died yesterday when his aircraft crashed while fighting fires on the NSW south coast.

The charter aircraft, contracted from Sydney Helicopters, is believed to have gone down when its red waterbombing bucket became snagged in the branches of a tree at Woodstock, near the Kingiman fire.

The pilot, Allan Tull, was the only person on board at the time of the incident and was killed in the crash.

Mr Tull has been remembered as an experienced and well-know pilot who had around 8000 hours of total flying time and 3000 hours of firefighting work in a helicopter.

"This is a deep tragedy,” NSW RFS Commissioner Shane Fitzsimmons said of the incident last night.

“This is really, really hurting a lot the RFS family, the firefighting family and the aerial community of NSW who work so closely together to try and save and protect the people of NSW."

The cause of the crash is being internally investigated by the NSW RFS.